proton discovery experiment

Ernest Rutherford bombarded nitrogen atoms with helium nuclei (alpha particles), and hydrogen atoms (protons) were formed as a result. From this, he concluded that nitrogen nuclei contained protons.

Please watch this as the best way to illustrate the Rutherford's experiment for the discovery of the proton.

Great question! Rutherford's main focus was on studying the nucleus through radioactive decay.

After the electron was discovered by Thomson in 1897 and after Rutherford's work on discovering the existence of the nucleus 1911, it was known that there must exist particles of positive charge to balance the negatively charged electrons to create electrically neutral atoms.

They immediately wondered what was left behind on the target after this process occurred. The conclusion was that the target captured the alpha particle (2+ charge) and emitted a proton (1+ charge), resulting in the target having a nuclear charge different than before. The target was now an isotope of another element. In the case of a nitrogen target, the nitrogen had a nuclear charge of 8 instead of seven, making it an isotope of oxygen This describes how the proton itself was discovered.

Many key experiments by Rutherford, his students, and others occurred before this and led to the understanding of the atom that is still the accepted model today.

A Science Journalist wrote the following information for ScienceLine in order to correct the historical error about the first man-made nuclear transmutation. We thank this person for their time and interest in providing reliable information to our audience.

For nearly 70 years, most scholars have incorrectly attributed the first man-made nuclear transmutation to Rutherford, however, the credit belongs to , a research fellow working under Rutherford. Between 1921 and 1924, Blackett performed the experiments that identified and proved the transmutation of nitrogen to oxygen. He published his results in 1925.

In 2016, I published a forensic historical examination of the early 20th century transmutation research in my book Lost History. In 2017, I communicated my findings to the U.S. Department of Energy, Office of History and Heritage Resources; the American Institute of Physics, Center for History of Physics; the Imperial College London, Physics Department (Home to Blackett's laboratory); and the Cambridge University, Physics Department (Home to Rutherford's laboratory). Each organization has now completed its own independent analysis, concurred, and corrected their respective Web sites. Here are the respective URLS:

• Privacy Policy

Read Chemistry

Discovery of the atom, nucleus, electron, proton, and neutron.

Read Chemistry November 27, 2018 General Chemistry

– In this subject, we will discuss the Discovery of the Atom, Nucleus, electron, Proton, and Neutron

Definition of atom

– Based on Dalton’s atomic theory , we can define an atom as the basic unit of an element that can enter into a chemical combination.

– Dalton imagined an atom that was both extremely small and indivisible.

– However, a series of investigations that began in the 1850s and extended into the twentieth century demonstrated that atoms possess internal structure; that is, they are made up of even smaller particles, which are called subatomic particles.

– This research led to the discovery of three such particles: electrons, protons, and neutrons.

Discovery of the electron 

– In the 1890s many scientists became caught up in the study of radiation, the emission and transmission of energy through space in the form of waves.

– Information gained from this research contributed greatly to our understanding of atomic structure.

– One device used to investigate this phenomenon was a cathode ray tube, the forerunner of the television tube (see Figure below).

(1) It is a glass tube from which most of the air has been evacuated.

(2) When the two metal plates are connected to a high-voltage source, the negatively charged plate, called the cathode, emits an invisible ray.

(3) The cathode ray is drawn to the positively charged plate, called the anode, where it passes through a hole and continues traveling to the other end of the tube.

(4) When the ray strikes the specially coated surface, it produces a strong fluorescence or bright light.

(5) In some experiments, two electrically charged plates and a magnet were added to the outside of the cathode ray tube (see Figure above).

(6) When the magnetic field is on and the electric field is off, the cathode ray strikes point A.

– When only the electric field is on, the ray strikes point C.

– When both the magnetic and the electric fields are off or when they are both on but balanced so that they cancel each other’s influence, the ray strikes point B.

– According to electromagnetic theory, a moving charged body behaves like a magnet and can interact with electric and magnetic fields through which it passes.

– Because the cathode ray is attracted by the plate bearing positive charges and repelled by the plate bearing negative charges, it must consist of negatively charged particles.

– We know these negatively charged particles as electrons.

Calculation of the mass of an electron

– An English physicist, J. J. Thomson, used a cathode ray tube and his knowledge of electromagnetic theory to determine the ratio of electric charge to the mass of an individual electron.

– The number he came up with is  – 1.76 x 10 8  C/g, where C stands for coulomb, which is the unit of electric charge.

– Thereafter, in a series of experiments carried out between 1908 and 1917, R. A. Millikan, an American physicist, found the charge of an electron to be – 1.6022 x 10 -19 C.

– From these data, he calculated the mass of an electron:

which is an exceedingly small mass.

Radioactivity

– In 1895, the German physicist Wilhelm Röntgen noticed that cathode rays caused glass and metals to emit very unusual rays.

– This highly energetic radiation penetrated matter, darkened covered photographic plates, and caused a variety of substances to fluoresce.

– Because these rays could not be deflected by a magnet, they could not contain charged particles as cathode rays do. Röntgen called them X rays.

– Not long after Röntgen’s discovery, Antoine Becquerel, a professor of physics in Paris, began to study the fluorescent properties of substances.

– Purely by accident, he found that exposing thickly wrapped photographic plates to a certain uranium compound caused them to darken, even without the stimulation of cathode rays.

– Like X-rays, the rays from the uranium compound were highly energetic and could not be deflected by a magnet, but they differed from X-rays because they were generated spontaneously.

– One of Becquerel’s students, Marie Curie, suggested the name radioactivity to describe this spontaneous emission of particles and/or radiation.

– Consequently, any element that spontaneously emits radiation is said to be radioactive .

Types of radioactive rays

– Further investigation revealed that three types of rays are produced by the decay, or breakdown, of radioactive substances such as uranium.

– Two of the three kinds are deflected by oppositely charged metal plates (Figure below):

Alpha (α) rays:  consist of positively charged particles, called α particles, and therefore are deflected by the positively charged plate.

Beta (β) rays, or β particles: are electrons and are deflected by the negatively charged plate.

gamma (γ) rays: The third type of radioactive radiation consists of high–energy rays.

– Like X-rays, γ rays have no charge and are not affected by an external electric or magnetic field.

– The figure shows Three types of rays emitted by radioactive elements.

– β rays consist of negatively charged particles (electrons) and are therefore attracted by the positively charged plate.

– The opposite holds for α rays— they are positively charged and are drawn to the negatively charged plate.

– Because γ rays have no charges, their path is unaffected by an external electric field.

Discovery of  the Proton and the Nucleus

– By the early 1900s, two features of atoms had become clear: They contain electrons, and they are electrically neutral.

– To maintain electrical neutrality, an atom must contain an equal number of positive and negative charges.

– Based on this information, Thomson proposed that an atom could be thought of as a uniform, positive sphere of matter in which electrons are embedded (Figure below).

– Thomson’s so-called “plum pudding” model was the accepted theory for several years.

– In 1910 the New Zealand physicist Ernest Rutherford, who had earlier studied with Thomson at Cambridge University, decided to use α particles to probe the structure of atoms.

– Together with his associate Hans Geiger and an undergraduate named Ernest Marsden, Rutherford carried out a series of experiments using very thin foils of gold and other metals as targets for α particles from a radioactive source (Figure below).

– They observed that:

(1) the majority of particles penetrated the foil either undeflected or with only a slight deflection.

(2) They also noticed that now and then an (a) particle was scattered (or deflected) at a large angle.

(3) In some instances, an α particle bounced back in the direction from which it had come! This was a most surprising finding, for in Thomson’s model the positive charge of the atom was so diffuse (spread out) that the positive α particles were expected to pass through with very little deflection.

(4) To quote Rutherford’s initial reaction when told of this discovery: “It was as incredible as if you had fired a 15-inch shell at a piece of tissue paper and it came back and hit you.

Figure shows: 

– (A) Rutherford’s experimental design for measuring the scattering of α particles by a piece of gold foil.

– Most of the (a) particles passed through the gold foil with little or no deflection.

– A few were deflected at wide angles. Occasionally an (a) particle was turned back. 

– (B) Magnified view of α particles passing through and being deflected by nuclei.

– To explain the results of the α-scattering experiment, Rutherford devised a new model of atomic structure, suggesting that most of the atom must be space.

– This structure would allow most of the α particles to pass through the gold foil with little or no deflection.

– The atom’s positive charges, Rutherford proposed, are all concentrated in the nucleus ,  a dense central core within the atom .

– Whenever an α particle came close to a nucleus in the scattering experiment, it experienced a large repulsive force and therefore a large deflection.

– Moreover, an (a) particle traveling directly toward a nucleus would experience an enormous repulsion that could completely reverse the direction of the moving particle.

– The positively charged particles in the nucleus  are called  protons .

– In separate experiments, it was found that the charge of each proton has the same magnitude as that of an electron and that the mass of the proton is 1.67262 x 10 -24  g —about 1840 times the mass of the oppositely charged electron.

– At this stage of the investigation, scientists perceived the atom as follows.

– The mass of a nucleus constitutes most of the mass of the entire atom, but the nucleus occupies only about 1/10 13  of the volume of the atom.

– We express atomic (and molecular) dimensions in terms of the SI unit called the picometer (pm).

1 pm =  1 x 10 -12   m

– A typical atomic radius is about 100 pm, whereas the radius of an atomic nucleus is only about 5 x 10 -3 pm.

– You can appreciate the relative sizes of an atom and its nucleus by imagining that if an atom were the size of a sports stadium, the volume of its nucleus would be comparable to that of a small marble.

– Although the protons are confined to the nucleus of the atom, the electrons are conceived of as being spread out about the nucleus at some distance from it.

Discovery of the Neutron

– Rutherford’s model of atomic structure left one major problem unsolved.

– It was known that hydrogen, the simplest atom, contains only one proton and that the helium atom contains two protons.

– Therefore, the ratio of the mass of a helium atom to that of a hydrogen atom should be 2:1. (Because electrons are much lighter than protons, their contribution can be ignored.) In reality, however, the ratio is 4:1.

– Rutherford and others postulated that there must be another type of subatomic particle in the atomic nucleus; the proof was provided by another English physicist, James Chadwick, in 1932.

– When Chadwick bombarded a thin sheet of beryllium with (a) particles, a very high energy radiation similar to γ rays was emitted by the metal.

– Later experiments showed that the rays consisted of electrically neutral particles having a mass slightly greater than that of protons . Chadwick named these particles  neutrons.

– The mystery of the mass ratio could now be explained.

– In the helium nucleus, there are two protons and two neutrons, but in the hydrogen nucleus there is only one proton and no neutrons; therefore, the ratio is 4:1.

– The figure shows the location of the elementary particles (protons, neutrons, and electrons) in an atom.

– There are other subatomic particles, but the electron, the proton, and the neutron are the three fundamental components of the atom that are important in chemistry.

– The table shows the masses and charges of these three elementary particles:

Reference: General Chemistry: The Essential Concepts / Raymond Chang, Jason Overby. (sixth edition) . 

Related Articles

Chemical Formula – Structural Formula

May 22, 2024

Atoms and Molecules

May 21, 2024

Heat and Temperature

May 20, 2024

Density and Specific gravity: Definition, Solved problems

May 19, 2024

Physical and Chemical properties of Matter

May 18, 2024

Solids, liquids, and gases.

May 16, 2024

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

Shop Our Online Science Store

3-in-1 alternative energy car diy stem kit.

• $19.99 $12.95

Wire Maze Electricity DIY STEM Kit

• $9.99 $4.95

Flashing LED Circuit DIY Electronics Kit

• $4.99 $2.59

Simple DC Motor DIY STEM Kit

Solar micro car kit diy stem kit, battery-powered balancing robot diy stem kit, solar & battery fan diy stem kit.

• $9.99 $5.95

Fan Micro Car DIY STEM Kit

• Privacy Policy
• Cookie Policy

Talk to our experts

1800-120-456-456

• Discovery of Protons and Neutrons

Who Discovered Proton?

The lowest unit of matter is an atom, which is made up of three subatomic particles: protons, neutrons, and electrons. The central nucleus is occupied by protons and neutrons, while electrons orbit the nucleus in specific orbits. During the nineteenth and twentieth centuries, these three subatomic particles were identified. Molecules are formed when atoms come together to create molecules, which interact to make matter (solid, liquid or gas).

In this article, We will discuss proton and neutrons and their discovery i.e. how proton/neutron was discovered and properties of protons and neutrons etc.

Discovery of Protons  

The presence of positively charged particles in an atom had been first observed in 1886 by E. Goldstein based on the concept that atoms are electrically neutral i.e., it has the same number of positive and negative charges. He performed a series of experiments and observed that when high voltage electricity passed through a cathode tube fitted with a perforated cathode (pierced disk) containing gas at low pressure a new type of ray was produced from the positive electrode (anode) which moves towards the cathode. These new rays he termed as canal rays, positive rays, or anode rays.  

(Image will be uploaded soon)

In 1909, Rutherford discovered protons in his famous gold foil experiment. He bombarded alpha particles on an ultrathin gold foil. Rutherford thought that a hydrogen nucleus must be the fundamental building block of all nuclei, and also possibly a new fundamental particle as well since nothing was known from the nucleus that was lighter. Based on Wilhelm Wien’s theory, who in 1898 discovered the proton in streams of ionized gas, Rutherford postulated the hydrogen nucleus to be a new particle in 1920, which he called proton. Rutherford named it the proton, from the Greek word "protos," meaning "first." 

What is a Proton?

“The fundamental particle of an atom, which is denoted by symbol p or p+. It has a positive electric charge of +1e elementary charge and a mass slightly less than that of a neutron”

The particles that are positively charged are called protons. A proton is usually represented as p its charge is “+1.” The number of protons in the nucleus of an atom is equal to the atomic number (Z) of the atom.

Mathematically it can be written as, 

Number of Protons = Atomic Number

For example, the atomic number of Krypton (Kr) atoms is 36. Hence, the nucleus of the Krypton atom contains 36 protons. 

Who Discovered Protons?

Goldstein observed positive rays in the anode ray experiment in 1886. In 1909, Rutherford discovered protons in his gold foil experiment.

How was Proton Discovered?

In a gold foil experiment, Rutherford bombarded alpha particles on an ultrathin gold foil and then detected the scattered alpha particles on a zinc sulphide (ZnS) screen. According to Rutherford’s observation,

Most of the alpha particles were not deflected; they passed through the foil. Some alpha particles get deflected at a small angle. Very few particles bounced back (1 in 20,000).

Based on these observations, Rutherford proposed the following: 

Most of the atom’s mass and its entire positive charge are confined in a small core, called a nucleus. The positively charged particle is called a proton.

Most of the volume of an atom is empty space.

The number of negatively charged electrons dispersed outside the nucleus is the same as the number of positively charged electrons in the nucleus. It explains the overall electrical neutrality of an atom.

Properties of Protons

Protons are also called Positive Rays or Anode Rays. Let us look at the properties of protons here.

They are positively charged.

They travel in straight lines and can cast shadows on the object placed in their path.

These positive rays are deflected by electric as well as magnetic fields. 

Mass of the proton is found to be 1.672 x 10 -24 g.

The charge on the proton is +1.602 x 10 -19 coulombs. 

The volume of a proton is given by 4/3 πr 3 (1.5 x 10 -38 cm 3 )

What is a Neutron?

Neutron can be Defined as “A subatomic particle of an atom denoted by n or n 0 . It has no net electric charge and a mass slightly greater than that of a proton.”

For his novel observation, Chadwick was awarded the Nobel Prize in 1935. It is to be noted here that except for hydrogen all atoms contain neutrons. Hydrogen atoms contain only a proton and an electron. 

Who Discovered Neutrons?

In his experiment, Chadwick bombarded beryllium atoms with high-energy alpha particles. He observed that some new particles are emitted which carry no charge, and the mass of this particle is the same as that of protons. A neutron is usually represented as “n” and its charge is zero.

The total number of protons and neutrons present in an atom indicates the mass number of that atom. 

Mass Number = (Number of Protons) + (Number of Neutrons)

Number of Neutrons = Mass Number - Atomic Number or number of protons

In the case of krypton, 

Mass number = 83.80

Protons = 36

83.80 = 36 + (Number of Neutrons)

Number of Neutrons = 83.80 – 36 = 47.8 or 48

How were Neutrons Discovered?

James Chadwick used a polonium source to fire alpha radiation at a beryllium sheet. As a result, uncharged, penetrating radiation was produced.

This radiation was incident on paraffin wax, which is a hydrocarbon with a high hydrogen concentration.

With the use of an ionisation chamber, the protons ejected from the paraffin wax (when impacted by the uncharged radiation) were seen.

Chadwick studied the interaction between the uncharged radiation and the atoms of numerous gases and measured the range of the freed protons.

He came to the conclusion that the unusually penetrating radiation was made up of uncharged particles with the mass of a proton (approximately). Neutrons were later given to these particles.

Properties of Neutrons

These are neutral particles.

The mass of neutrons is equal to that of protons (the Mass of the neutron is 1.675 x 10 -24 g).

The specific charge of a neutron is zero.

The density of the neutron is 1.5 x 10 14 g/cc.

What are Electrons?

The electron is defined as a subatomic particle having a negative one elementary electric charge. Electrons are said to be the first generation of the lepton particle family. It is because they have zero known components or substructures, and because of this, they are considered elementary particles.

Discovery of Electrons

In 1897, J.J. Thomson discovered electrons by working on a cathode ray tube. Thomson demonstrated that cathode rays were negatively charged by passing high voltage electricity through a cathode tube containing a gas at low pressure. He observed a new type of ray was produced from a negative electrode (cathode) which moves towards the anode. These new rays of particles were called cathode rays (as they come out of cathode). The key characteristics of cathode rays are as follows:

They travel in a straight line.

They carry mass and possess kinetic energy.

The mass and charge of the cathode ray particles are independent of the nature of the gas taken in the discharge tube.

An electron is usually represented as “e” and its charge is “-1”.  An electron can be defined as:

“The fundamental particle of an atom, which has a negative one elementary charge and it is denoted by e−. It has mass approximately 1/1836 that of the proton.”

Atoms do not carry any specific electrical charge. Therefore, a balance between the protons and the electrons is necessary for which atoms contain equal numbers of protons and electrons. 

Number of Electrons = Number of Protons = Atomic Number

For example, the nucleus of an atom of krypton has 36 protons in it. The balance between protons and electrons is maintained when a krypton atom has 36 electrons.

Properties of Electrons

The specific charge (e/m) of electrons was found by Thomson as 1.76 x 10 8 coulomb/gram. The specific charge of electrons decreases with an increase in velocity . It is due to an increase in velocity which otherwise increases the mass of electrons. 

The radius of the electron is found to be 10 -15 cm.

The density of electrons was found to be 2.17 x 10 17 g/cc.

Charge on one mole of the electron is 96500 coulombs or 1 faraday. 

Discovery of Electrons, Protons and Neutrons

The above article is very knowledge full and interesting as it deals with the discovery of protons and neutrons. The properties of neutron and proton are also discussed. Along with this discovery of electrons is also mentioned.

FAQs on Discovery of Protons and Neutrons

1. What exactly is Dalton's theory?

Dalton's atomic theory was the first systematic attempt to define all matter in terms of atoms and their properties. According to the first component of his theory, all matter is made up of indivisible atoms. The second component of the theory states that all atoms of a given element have the same mass and properties.

2. Who was the first to propose an atomic theory?

In the 5th century BC, Greek philosophers Leucippus and Democritus proposed the old atomic idea, which was revived in the 1st century BC by the Roman philosopher and poet Lucretius.

3. Who named the atom?

Democritus. However, we must travel back to 400 B.C. Greece to understand the word atom. Then there was Democritus, a brilliant philosopher who coined the term "atomos," which means "uncuttable" in Greek. As a result, all matter might be reduced to unique, small particles known as atomos, he suggested.

NCERT Study Material

An editorially independent publication supported by the Simons Foundation.

Get the latest news delivered to your inbox.

Type search term(s) and press enter

• Comment Comments
• Save Article Read Later Read Later

Inside the Proton, the ‘Most Complicated Thing You Could Possibly Imagine’

October 19, 2022

Researchers recently discovered that the proton sometimes includes a charm quark and charm antiquark, colossal particles that are each heavier than the proton itself.

Samuel Velasco/Quanta Magazine

Introduction

More than a century after Ernest Rutherford discovered the positively charged particle at the heart of every atom, physicists are still struggling to fully understand the proton.

High school physics teachers describe them as featureless balls with one unit each of positive electric charge — the perfect foils for the negatively charged electrons that buzz around them. College students learn that the ball is actually a bundle of three elementary particles called quarks. But decades of research have revealed a deeper truth, one that’s too bizarre to fully capture with words or images.

“This is the most complicated thing that you could possibly imagine,” said Mike Williams , a physicist at the Massachusetts Institute of Technology. “In fact, you can’t even imagine how complicated it is.”

The proton is a quantum mechanical object that exists as a haze of probabilities until an experiment forces it to take a concrete form. And its forms differ drastically depending on how researchers set up their experiment. Connecting the particle’s many faces has been the work of generations. “We’re kind of just starting to understand this system in a complete way,” said Richard Milner , a nuclear physicist at MIT.

As the pursuit continues, the proton’s secrets keep tumbling out. Most recently, a monumental data analysis published in August found that the proton contains traces of particles called charm quarks that are heavier than the proton itself.

The proton “has been humbling to humans,” Williams said. “Every time you think you kind of have a handle on it, it throws you some curveballs.”

Recently, Milner, together with Rolf Ent at Jefferson Lab, MIT filmmakers Chris Boebel and Joe McMaster, and animator James LaPlante, set out to transform a set of arcane plots that compile the results of hundreds of experiments into a series of animations of the shape-shifting proton. We’ve incorporated their animations into our own attempt to unveil its secrets.

Cracking Open the Proton

Proof that the proton contains multitudes came from the Stanford Linear Accelerator Center (SLAC) in 1967. In earlier experiments, researchers had pelted it with electrons and watched them ricochet off like billiard balls. But SLAC could hurl electrons more forcefully, and researchers saw that they bounced back differently. The electrons were hitting the proton hard enough to shatter it — a process called deep inelastic scattering — and were rebounding from point-like shards of the proton called quarks. “That was the first evidence that quarks actually exist,” said Xiaochao Zheng , a physicist at the University of Virginia.

After SLAC’s discovery, which won the Nobel Prize in Physics in 1990, scrutiny of the proton intensified. Physicists have carried out hundreds of scattering experiments to date. They infer various aspects of the object’s interior by adjusting how forcefully they bombard it and by choosing which scattered particles they collect in the aftermath.

By using higher-energy electrons, physicists can ferret out finer features of the target proton. In this way, the electron energy sets the maximum resolving power of a deep inelastic scattering experiment. More powerful particle colliders offer a sharper view of the proton.

Higher-energy colliders also produce a wider array of collision outcomes, letting researchers choose different subsets of the outgoing electrons to analyze. This flexibility has proved key to understanding quarks, which careen about inside the proton with different amounts of momentum.

By measuring the energy and trajectory of each scattered electron, researchers can tell if it has glanced off a quark carrying a large chunk of the proton’s total momentum or just a smidgen. Through repeated collisions, they can take something like a census — determining whether the proton’s momentum is mostly bound up in a few quarks, or distributed over many.

Even SLAC’s proton-splitting collisions were gentle by today’s standards. In those scattering events, electrons often shot out in ways suggesting that they had crashed into quarks carrying a third of the proton’s total momentum. The finding matched a theory from Murray Gell-Mann and George Zweig, who in 1964 posited that a proton consists of three quarks.

Gell-Mann and Zweig’s “quark model” remains an elegant way to imagine the proton. It has two “up” quarks with electric charges of +2/3 each and one “down” quark with a charge of −1/3, for a total proton charge of +1.

Three quarks careen about in this data-driven animation.

MIT/Jefferson Lab/Sputnik Animation

But the quark model is an oversimplification that has serious shortcomings.

It fails, for instance, when it comes to a proton’s spin, a quantum property analogous to angular momentum. The proton has half a unit of spin, as do each of its up and down quarks. Physicists initially supposed that — in a calculation echoing the simple charge arithmetic — the half-units of the two up quarks minus that of the down quark must equal half a unit for the proton as a whole. But in 1988, the European Muon Collaboration reported that the quark spins add up to far less than one-half. Similarly, the masses of two up quarks and one down quark only comprise about 1% of the proton’s total mass. These deficits drove home a point physicists were already coming to appreciate: The proton is much more than three quarks.

Much More Than Three Quarks

The Hadron-Electron Ring Accelerator (HERA), which operated in Hamburg, Germany, from 1992 to 2007, slammed electrons into protons roughly a thousand times more forcefully than SLAC had. In HERA experiments, physicists could select electrons that had bounced off of extremely low-momentum quarks, including ones carrying as little as 0.005% of the proton’s total momentum. And detect them they did: HERA’s electrons rebounded from a maelstrom of low-momentum quarks and their antimatter counterparts, antiquarks.

Many quarks and antiquarks seethe in a roiling particle “sea.”

The results confirmed a sophisticated and outlandish theory that had by then replaced Gell-Mann and Zweig’s quark model. Developed in the 1970s, it was a quantum theory of the “strong force” that acts between quarks. The theory describes quarks as being roped together by force-carrying particles called gluons. Each quark and each gluon has one of three types of “color” charge, labeled red, green and blue; these color-charged particles naturally tug on each other and form a group — such as a proton — whose colors add up to a neutral white. The colorful theory became known as quantum chromodynamics, or QCD.

According to QCD, gluons can pick up momentary spikes of energy. With this energy, a gluon splits into a quark and an antiquark — each carrying just a tiny bit of momentum — before the pair annihilates and disappears. It’s this “sea” of transient gluons, quarks and antiquarks that HERA, with its greater sensitivity to lower-momentum particles, detected firsthand.

HERA also picked up hints of what the proton would look like in more powerful colliders. As physicists adjusted HERA to look for lower-momentum quarks, these quarks — which come from gluons — showed up in greater and greater numbers. The results suggested that in even higher-energy collisions, the proton would appear as a cloud made up almost entirely of gluons.

The gluon dandelion is exactly what QCD predicts. “The HERA data are direct experimental proof that QCD describes nature,” Milner said.

But the young theory’s victory came with a bitter pill: While QCD beautifully described the dance of short-lived quarks and gluons revealed by HERA’s extreme collisions, the theory is useless for understanding the three long-lasting quarks seen in SLAC’s gentle bombardment.

QCD’s predictions are easy to understand only when the strong force is relatively weak. And the strong force weakens only when quarks are extremely close together, as they are in short-lived quark-antiquark pairs. Frank Wilczek, David Gross and David Politzer identified this defining feature of QCD in 1973, winning the Nobel Prize for it 31 years later.

But for gentler collisions like SLAC’s, where the proton acts like three quarks that mutually keep their distance, these quarks pull on each other strongly enough that QCD calculations become impossible. Thus, the task of further demystifying the three-quark view of the proton has fallen largely to experimentalists. (Researchers who run “digital experiments,” in which QCD predictions are simulated on supercomputers, have also made key contributions .) And it’s in this low-resolution picture that physicists keep finding surprises.

A Charming New View

Recently, a team led by Juan Rojo of the National Institute for Subatomic Physics in the Netherlands and VU University Amsterdam analyzed more than 5,000 proton snapshots taken over the last 50 years, using machine learning to infer the motions of quarks and gluons inside the proton in a way that sidesteps theoretical guesswork.

  The new scrutiny picked up a background blur in the images that had escaped past researchers. In relatively soft collisions just barely breaking the proton open, most of the momentum was locked up in the usual three quarks: two ups and a down. But a small amount of momentum appeared to come from a “charm” quark and charm antiquark — colossal elementary particles that each outweigh the entire proton by more than one-third.

The proton sometimes acts like a “molecule” of five quarks.

Short-lived charms frequently show up in the “quark sea” view of the proton (gluons can split into any of six different quark types if they have enough energy). But the results from Rojo and colleagues suggest that the charms have a more permanent presence, making them detectable in gentler collisions. In these collisions, the proton appears as a quantum mixture, or superposition, of multiple states: An electron usually encounters the three lightweight quarks. But it will occasionally encounter a rarer “molecule” of five quarks, such as an up, down and charm quark grouped on one side and an up quark and charm antiquark on the other.

Such subtle details about the proton’s makeup could prove consequential. At the Large Hadron Collider, physicists search for new elementary particles by bashing high-speed protons together and seeing what pops out; to understand the results, researchers need to know what’s in a proton to begin with. The occasional apparition of giant charm quarks would throw off the odds of making more exotic particles.

And when protons called cosmic rays hurtle here from outer space and slam into protons in Earth’s atmosphere, charm quarks popping up at the right moments would shower Earth with extra-energetic neutrinos , researchers calculated in 2021. These could confound observers searching for high-energy neutrinos coming from across the cosmos.

Rojo’s collaboration plans to continue exploring the proton by searching for an imbalance between charm quarks and antiquarks. And heavier constituents, such as the top quark, could make even rarer and harder-to-detect appearances.

Next-generation experiments will seek still more unknown features. Physicists at Brookhaven National Laboratory hope to fire up the Electron-Ion Collider in the 2030s and pick up where HERA left off, taking higher-resolution snapshots that will enable the first 3D reconstructions of the proton. The EIC will also use spinning electrons to create detailed maps of the spins of the internal quarks and gluons, just as SLAC and HERA mapped out their momentums. This should help researchers to finally pin down the origin of the proton’s spin, and to address other fundamental questions about the baffling particle that makes up most of our everyday world.

Correction: October 20, 2022 A previous version of the article erroneously implied that lower-momentum quarks live shorter lives than higher-momentum quarks in the quark sea. The text has been updated to clarify that all these quarks are lower-momentum and shorter-lived than those in the three quark-picture.

Get highlights of the most important news delivered to your email inbox

Also in Multimedia

Quanta Relaunches Hyperjumps Math Game

Hyperjumps Math Game

The Quest to Decode the Mandelbrot Set, Math’s Famed Fractal

Comment on this article.

Quanta Magazine moderates comments to facilitate an informed, substantive, civil conversation. Abusive, profane, self-promotional, misleading, incoherent or off-topic comments will be rejected. Moderators are staffed during regular business hours (New York time) and can only accept comments written in English. 

Next article

Use your social network.

Forgot your password ?

We’ll email you instructions to reset your password

Enter your new password

ResearchTweet

Discovery of protons: model, discovery, and experiment.

• Reading time: 5 mins read

What are Protons?

The three different sub-atomic particles present in the nuclei of an atom are called, protons, neutrons, and electrons and they were discovered in the nineteenth and twentieth century.

Discovery of Protons

The nucleus of the atom was discovered by a scientist named Ernest Rutherford in the year 1911 in his well-known gold foil experiment. He stated that all the positively charged particles present in an atom were concentrated in a singular core and that maximum of the atom’s volume was empty.

He also stated that the total number of positively charged particles present in the nucleus of an atom is always equal to the total number of negatively charged electrons present around it.

The finding of the proton is credited to Ernest Rutherford, who showed that the nucleus of the hydrogen atom (that is a proton) is present in the nuclei of all atoms in the year 1917. But, the presence of a positively charged particle found in an atom had been first noticed by E. Goldstein in the year 1886 based on the concept that atoms are generally electrically neutral which means that they have the same number of positive and negative charges.

He performed a series of experiments and detected that when high voltage electricity was passed through a cathode tube which was fitted with a perforated cathode (pierced disk) and thus contained gas at low pressure then a new type of ray was produced from a positive electrode or commonly called as the anode which moved towards the cathode.

These new rays he named as canal rays, positive rays, or anode rays. Further, the canal Ray experiment is the experiment that was performed by German scientist Eugen Goldsteinin that led to the discovery of the proton. The discovery of proton occurred after the discovery of the electron which further supported the structure of the atom.

The Canal Ray Experiment

• The apparatus as shown above in the figure is set by providing a very high voltage source and emptying the air to preserve low pressure inside the tube.

• High voltage is thus passed to the two metal pieces as shown to ionize the air and hence making it a conductor of electricity.

• The electricity started to flow as the circuit completes.

• When the voltage was increased further to several thousand volts, then a faint luminous ray was observed extending from the holes in the back of the cathode.

• The rays thus observed were moving in the opposite direction of cathode rays and were termed as canal rays.

Conclusion of Canal Ray Experiments

• As compared to cathode rays, canal rays depend upon the nature of gas present in that tube. It is because of the fact that the canal rays consisted of positive ionized ions which were formed by the ionization of gas present in the tube.

• The behavior of particles present in an electric and magnetic field was thus the opposite to that of cathode rays.

Protons Characteristic

Protons are referred to as the positively charged subatomic particles of an atom. It is represented by the symbol p or p + .

A hydrogen atom comprises of one proton and one electron, so when an electron is removed from the hydrogen atom then a proton is produced. This is the reason why the proton is also represented as H + .

It thus possesses +1e (or 1.60 10 -19 coulomb) positive electric charge.

The word Proton is a Greek word that means ‘First’. It was initially used by Ernest Rutherford in the year 1920. The subatomic particles protons and neutrons are collectively known as nucleons.

What is The Mass of Protons?

The mass of the proton is 1.67 10 -24 gram or 1.67 10 -27 kg.

The mass of an electron is equal to 9.1 10 -28 consequently the mass of a proton is 1836 times the mass of an electron. Though the mass of a proton is almost always equal to the mass of a neutron present in the nuclei of an atom.

The number of protons present inside the nucleus of an atom is always equal to the atomic number (Z) of the atom.

Mathematically,

Number of Protons = Atomic Number

For instance, the atomic number of the Krypton (Kr) atom is equal to 36. Henceforth, the nucleus of the Krypton atom consists of 36 protons.

Properties of Protons / Positive Rays / Anode Rays

1. They are positively charged ions.

2. They travel in straight lines and thus can cast a shadow of the thing located in their path.

3. These positive rays are also deflected by electric as well as a magnetic field.

4. Mass of proton is equal to 1.672 x 10 -24 g.

5. The charge on the proton is equal to +1.602 x 10 -19 coulombs.

Discovery of Neutrons: Model, Discovery, and Experiment

Protons citations.

• Discovery of new proton emitters 160Re and 156Ta. Phys Rev Lett . 1992 Mar 2;68(9):1287-1290.
• Particle therapy and treatment of cancer. Lancet Oncol . 2006 Aug;7(8):676-85.

Similar Post:

Postdoc Salary and Expenses in All 50 States in United States 2024

7+ Letter of Recommendation Templates for Doctoral Program

The Benefits of Dietary Protease: The Secret to Healthier Body

Is Your Child’s Bone Health at Risk? The Dangers of Smoking While Pregnant

How Pharmaceuticals Are Polluting Our Waters?

How Blue Light is Secretly Speeding Up Aging—A New Study Reveals

How Opioid Alters Brain Synapses Before Birth?

How Microbes Help Plants Shine Under Stress?

A New Path to Combat Obesity and Liver Disease

The Secret Weapon Plants Use to Outsmart Their Neighbors

Breaking Barriers in Alzheimer’s Research

A New Target in the Fight Against Colorectal Cancer

Leave a reply cancel reply.

Save my name, email, and website in this browser for the next time I comment.

Scientists make lab-grown black hole jets

By using protons to probe how a magnetic field responds to an expanding plasma, experimenters have replicated the particle jets spewed out by active black holes.

An experiment using beams of protons to probe how plasma and magnetic fields interact may have just solved the mystery of how quasars and other active supermassive black holes unleash their relativistic jets.

Let's picture the scene at the heart of a quasar. A supermassive black hole , perhaps hundreds of millions — or even billions — of times the mass of our sun , is ravenously devouring matter that is streaming into its maw from a spiraling, ultra-hot disk. That charged matter is called plasma, and it gets gravitationally drawn into the black hole's surroundings — however, not all of the plasma, which is made from ionized, or electrified, atoms shorn of electrons, is swallowed by the black hole. Indeed, the black hole bites off more than it can chew, and some of the plasma is spat out in jets collimated by the black hole's powerful magnetic field before that plasma gets anywhere near the event horizon, which is basically the point of no return.

These jets can stretch thousands of light-years into space. Yet, explaining the physics that takes place at the base of the jet, where they're formed, has eluded scientists.

The answer may have come from researchers at the Princeton Plasma Physics Laboratory (PPPL) in New Jersey, who were able to devise a modification to a plasma-measuring technique called proton radiography.

In their experiment, the researchers first created a high-energy density plasma by firing a pulsed, 20-joule laser beam at a plastic target. Then, they used powerful lasers to instigate nuclear fusion in a fuel capsule filled with deuterium and helium-3. The fusion reactions released bursts of protons and X-rays.

Related: 'Final parsec problem' that makes supermassive black holes impossible to explain could finally have a solution

These protons and X-rays then passed through a nickel mesh filled with tiny holes. Think of the mesh as like a colander for straining pasta; it strains the protons into many discrete beams that then can measure how the expanding plasma plume interacts with a background magnetic field. Because the protons are charged, they'll follow the magnetic field lines as they are buffeted by the plasma. The X-ray burst acts as a check — because the X-rays pass cleanly through the mesh and the magnetic field, they provide an undistorted image of the plasma to compare to the proton beam measurements.

Sign up for the Live Science daily newsletter now

Get the world’s most fascinating discoveries delivered straight to your inbox.

"Our experiment was unique because we could directly see the magnetic field changing over time," said Will Fox, the experiment's principal investigator, in a statement . "We could directly observe how the field gets pushed out and responds to the plasma in a type of tug-of-war."

They observed in detail the magnetic field bending outward under pressure from the expanding plasma, with the plasma sloshing against the magnetic field lines. This bubbling and frothing of the plasma is known as magneto-Rayleigh Taylor instability, and it created shapes in the magnetic field that look like whirls and mushrooms. Crucially, as the plasma energy decreased, the magnetic field lines were able to snap back. This compressed the plasma into a straight, narrow column not unlike a quasar's relativistic jet.

"When we did the experiment and analyzed the data, we discovered we had something big," said PPPL's Sophia Malko. "Observing magneto-Rayleigh Taylor instabilities arising from the interaction of plasma and magnetic fields had long been thought to occur but had never been directly observed until now. This observation helps confirm that this instability occurs when expanding plasma meets magnetic fields."

The experiment strongly indicates that quasar jets can thank this sort of reaction of magnetic fields to the expanding plasma for their creation. If the results are a snapshot of what happens around active black holes, that would mean, in the black hole's accretion disk, conditions become so intense that the plasma in the disk is able to push against the tightly packed magnetic field lines, which can then snap back and push the plasma into a narrow column, almost squirting it away from the black hole. If true, this might be a huge missing piece in our picture of how active black holes operate.

— Some black holes have a 'heartbeat' — and astronomers may finally know why

— Watch a star get destroyed by a supermassive black hole in the 1st simulation of its kind

— Astronomers find black hole's favorite snack: 'The star appears to be living to die another day'

"Now that we have measured these instabilities very accurately, we have the information we need to improve our models and potentially simulate and understand astrophysical jets to a high degree than before," said Malko. "It's interesting that humans can make something in a laboratory that usually exists in space."

The findings were published on June 27 in the journal Physical Review Research .

Originally published on Space.com .

Some black holes have a 'heartbeat' — and astronomers may finally know why

Watch a star get destroyed by a supermassive black hole in the 1st simulation of its kind

Giant oarfish: The 'doomsday' fish of legend that supposedly foreshadows earthquakes

Most Popular

• 2 Why doesn't stainless steel rust?
• 3 'Sensational discovery' of 2,000-year-old Roman military camp found hidden in the Swiss Alps
• 4 New tick-borne virus discovered in China can affect the brain, scientists report
• 5 Watch Live: Boeing Starliner is about to return to Earth without its crew

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

• View all journals
• Explore content
• About the journal
• Publish with us
• Sign up for alerts
• Open access
• Published: 07 September 2024

Stabilized Cu 0 -Cu 1+ dual sites in a cyanamide framework for selective CO 2 electroreduction to ethylene

• Kaihang Yue   ORCID: orcid.org/0000-0002-0398-9286 1 , 2   na1 ,
• Yanyang Qin 3   na1 ,
• Honghao Huang 1 ,
• Zhuoran Lv 1 , 4 ,
• Mingzhi Cai   ORCID: orcid.org/0009-0007-4598-9325 4 , 5 ,
• Yaqiong Su   ORCID: orcid.org/0000-0001-5581-5352 3 ,
• Fuqiang Huang   ORCID: orcid.org/0000-0003-0526-5473 1 , 4 &
• Ya Yan   ORCID: orcid.org/0000-0002-9269-4235 1 , 2  

Nature Communications volume  15 , Article number:  7820 ( 2024 ) Cite this article

2 Altmetric

Metrics details

• Electrocatalysis

Electrochemical reduction of carbon dioxide to produce high-value ethylene is often limited by poor selectivity and yield of multi-carbon products. To address this, we propose a cyanamide-coordinated isolated copper framework with both metallic copper (Cu 0 ) and charged copper (Cu 1+ ) sites as an efficient electrocatalyst for the reduction of carbon dioxide to ethylene. Our operando electrochemical characterizations and theoretical calculations reveal that copper atoms in the Cu δ+ NCN complex enhance carbon dioxide activation by improving surface carbon monoxide adsorption, while delocalized electrons around copper sites facilitate carbon-carbon coupling by reducing the Gibbs free energy for *CHC formation. This leads to high selectivity for ethylene production. The Cu δ+ NCN catalyst achieves 77.7% selectivity for carbon dioxide to ethylene conversion at a partial current density of 400 milliamperes per square centimeter and demonstrates long-term stability over 80 hours in membrane electrode assembly-based electrolysers. This study provides a strategic approach for designing catalysts for the electrosynthesis of value-added chemicals from carbon dioxide.

Similar content being viewed by others

Selective and energy-efficient electrosynthesis of ethylene from CO 2 by tuning the valence of Cu catalysts through aryl diazonium functionalization

Directing CO 2 electroreduction pathways for selective C 2 product formation using single-site doped copper catalysts

Stabilizing copper sites in coordination polymers toward efficient electrochemical C-C coupling

Introduction.

Carbon conversion via electrochemical CO 2 reduction reaction (CO 2 RR) provides a promising solution to mitigate rising CO 2 levels and simultaneously production of fuels and value-added feedstocks 1 , 2 , 3 . Relative to the research on C 1 products, higher C 2 hydrocarbons, such as ethylene (C 2 H 4 ), is a more high-value-added product but suffer from difficulty of effective C–C coupling in CO 2 RR process 4 , 5 , 6 . A key challenge facing the current CO 2 RR electrocatalyst is how to improve energy efficiency by enhancing a single-product Faradaic efficiency (FE) with low overpotentials while keeping the catalyst durability at elevating current density 7 , 8 . Among various electrocatalysts, copper oxidation states preserved materials are known to be the most effective for CO 2 -to-C 2 H 4 conversion. However, the self-reduction and undesirable reconstruction makes these copper-based catalysts offering limited activity and selectivity to the desirable C 2 H 4 production 9 , 10 .

Recently, it has been revealed that manipulating oxidation states to achieve the well balance of Cu 0 and Cu 1+ during CO 2 RR is vital for CO 2 -to-C 2 H 4 11 , 12 , 13 . It is found the Cu 0 site can activate CO 2 and facilitate the following electron transfers, while the Cu 1+ site strengthens the adsorption of adsorbed CO (*CO) and boosts C–C coupling to afford effective production of C 2 H 4 14 , 15 , 16 . Several representative reports constructing reversible transformation process to stabilize the Cu 0 -Cu 1+ ensembles on the designed copper oxides, or the support assisted copper oxides (Fig.  1a, i ) 17 , 18 , 19 . However, the C 2 conversion mostly limited at small potential window as the catalysts would behave copper-like CO 2 RR performance at a higher cathodic potential. Although constructing synergistic Cu 0 -Cu 1+ interfaces via Cu-based heterogeneous ( e.g . Cu/Cu x S x , Cu/CuPO) materials can increase the current density of CO 2 RR and achieve a highly selective, but instability currently happens due to the solubility of polysulfide or polyphosphate, during long-term high redox potentials (Fig.  1a, ii ) 20 , 21 , 22 .

a Schematic illustration of the construction of Cu 0 -Cu 1+ catalytic sites: (i) Electrochemical induction. (ii) Heterojunction interface. (iii) Stabilized Cu 0 -Cu 1+ dual sites via cyanamide framework (this work). b XRD patterns of Cu δ+ NCN, CuNCN and CuO. c SEM and ( d ) TEM images of Cu δ+ NCN. e FFT diagrams of of Cu δ+ NCN. f Aberration-corrected HAABF-STEM images of Cu δ+ NCN along the [001] zone. g EDS mapping of Cu δ+ NCN.

Inspired by the strengths and weaknesses of these strategies, finely coordinating Cu 0 -Cu 1+ ensembles with [NCN] 2− group to form multi-atom ion-composed compounds different from oxides and chalcogenides will maximize the potential of such models and thus achieve the co-existence of Cu 0 and Cu 1+ dual sites in the framework, where the isolated Cu 0 can strongly conjugate with the Cu–N in Cu 2 NCN (Fig.  1a, iii ). The advantage of such structure lies in the cyanamide anions [NCN] 2− , on one hand, is a strongly σ -donating ligand can delocalize Cu d -electrons, on the other hand, π electrons flowing among [N–C≡N] 2− or [N≡C–N] 2− or [N=C=N] 2− bonds would potentially improve electrons conductivity and thus prevent the Cu + from self-reduction 23 , 24 , 25 . Moreover, the spacious crystal structure resulted from parallel aligned [NCN] 2− would maximum exposure of the active sites and brings about abundant channel for the adsorption of reagents.

Focusing on this vision, we herein proposed an isolated metallic Cu atom conjugated Cu 2 NCN framework (donated as Cu δ+ NCN) by the structure cleavage of CuNCN to trigger a phase transition via a stepwise reduction strategy, which worked as a robust catalytic model to stabilize the copper oxidation state for high CO 2 RR activity and selectivity for C 2 H 4 . Specifically, aberration-corrected transmission electron microscope (AC-TEM), synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy and extended X-ray absorption fine structure (EXAFS) studies consistently confirmed that the linear [NCN] 2− anions in the Cu δ+ NCN open framework stabilize the Cu 0 -Cu 1+ ensembles by strong covalent interactions and the fast electrons transfer nature, which afforded the highly active Cu δ+ species maintaining well balance of Cu 0 -Cu 1+ dual sites rather than the evolution of self-reduced Cu 0 metal during the CO 2 RR. Furthermore, combined results of operando X-ray absorption spectroscopy (XAS), operando attenuated total reflection-surface enhanced infrared absorption spectroscopy (ATR-SEIRA) and density functional theory (DFT) simulation, the synergetic effect of isolated Cu 0 sites and positively charged Cu 1+ was elucidated that the Cu 0 sites can adsorb and activate the CO 2 while the neighboring Cu 1+ sites accelerated the C–C coupling and enabled a highly selective conversion of CO 2 to C 2 H 4 . Benefitting from the [NCN] 2− open framework stabilized Cu 0 -Cu 1+ ensembles, Cu δ+ NCN exhibited an exceptional catalytic selectivity featuring a C 2 H 4 Faradaic efficiency higher than 75% at 400 mA cm −2 over a 15 h constant CO 2 RR. Significantly, such rationally designed active sites/conductive group coordinated open framework could provide valuable insights for the development of highly selective and stable CO 2 RR catalysts for the electrosynthesis of higher-value products.

Results and discussion

Structural characterizations of cu δ+ ncn.

A conventional CuNCN prepared from a liquid-phase precipitation was chemically cleaved by hydrazine acting as reduction agent to fabricate the Cu δ+ NCN structure composed of soft Cu (Cu 1+ ) and hard Cu (Cu 0 ) dual sites that stabilized by [NCN] 2− group (Methods in Supporting Information). The X-ray diffraction (XRD) pattern of Cu δ+ NCN displayed a monoclinic phase that similar to the Cu 2 NCN (Fig.  1b ). For comparison, CuNCN and CuO nanostructures were also synthesized with similar method (Fig.  2a and Supplementary Figs.  1 , 2 ). Scanning electronic microscopy (SEM) image revealed the as-prepared Cu δ+ NCN display a morphology of assembled nanosheets (Fig.  1c ), this is further verified by transmission electron microscopy (TEM) characterization, where well-defined nanosheet with a thickness of 14 nm was observed (Fig.  1d , Supplementary Fig.  3 ). Significant polycrystalline diffraction signals appear on the (001), (021) and (020) faces of the monoclinic Cu δ+ NCN in the Fast Fourier transform (FFT) map of the [001] region (Fig.  1e ).The high-angle annular bright-field (HAABF) images of scanning transmission electron microscope (STEM) along the [001] zone indicated that the local atomic distribution and crystal structure were consistent with monoclinic Cu 2 NCN (Fig.  1f ; Supplementary Fig  4 ). Additionally, the energy dispersive spectroscopy (EDS) mapping analysis of Cu δ+ NCN pointed out the uniform distribution of Cu, N and C elements throughout the nanosheet (Fig.  1g ). The elemental content of Cu was confirmed to be 67.23% by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), in comparison to the 60.45% in CuNCN, this can be attributed to the reduction by hydrazine hydrate leading to a decrease in the [NCN] 2− group ratio. (Supplementary Table  1 ).

a Cu LMM spectra of Cu δ+ NCN, CuNCN and CuO. b Normalized Cu K-edge XANES spectra and c the derived normalized χμ ( E ) spectra of Cu δ+ NCN, CuNCN, CuO, Cu foil and standard Cu 2 O samples. d FT-EXAFS spectra of Cu δ+ NCN, CuNCN, CuO, Cu foil and standard Cu 2 O samples. e Surface potential profiles of Cu δ+ NCN, CuNCN and CuO. f FT-IR spectra of Cu δ+ NCN, CuNCN and CuO.

X-ray photoelectron spectroscopy (XPS) was conducted to investigate the surface composition and chemical states of Cu δ+ NCN (Supplementary Fig.  5 ). From the deconvoluted Cu 2 p spectra, two peaks centered at 932.80 and 952.68 eV were assigned to 2 p 3/2 and 2 p 1/2 of Cu 0 or Cu 1+ species, respectively (Supplementary Fig.  5b ). Auger emission spectrum (AES) of Cu LMM further suggested the coexistence of Cu 0 and Cu 1+ in Cu δ+ NCN (Fig.  2a ). Then, X-ray absorption spectroscopy (XAS) was performed to analyze the electronic structure and local coordination environment of Cu in Cu δ+ NCN. The X-ray absorption near edge structure (XANES) spectra together with the first-order derivative revealed the valence state of Cu in Cu δ+ NCN is located between Cu 1+ and Cu 0 (Fig.  2 b, c ) 26 . The Fourier transform k 3 -weighted Cu K-edge extended X-ray absorption fine structure (EXAFS) spectra revealed that both Cu–N region (with a distance of ∼  1.5 Å) and Cu–Cu region (with a distance of 2.18 Å) were observed in Cu δ+ NCN (Fig.  2d ). The Cu–N/C/O coordination number (CN) of Cu δ+ NCN was confirmed to be 1.6, smaller than that of Cu 2 NCN (CN = 2) in the first coordination layer by fitting the EXAFS spectra (Supplementary Tables  2 , 3 ). By integrating the structural information observed from Cu δ+ NCN: the Cu–N/C/O coordination number in EXAFS being less than the theoretical value, the average valence state residing between 0 and +1 in the XAS K-edge, and the presence of both Cu 0 and Cu 1+ atoms indicated by the Cu LMM Auger spectrum, we can deduce that both Cu 0 and Cu 1+ coexist on the surface of Cu δ+ NCN. To evaluate the charge states at the Cu δ+ NCN, the distribution of surface electrostatic potential was measured by using Kelvin probe force microscopy (KPFM) in atomic force microscopy (AFM). Figure  2e and Supplementary Fig.  3 showed the respective surface electrostatic potential maps and the intensity profiles across the samples, where the intensities correspond to the relative surface potentials and a smaller surface electrostatic potential would endow the catalyst good CO 2 adsorption and electron transfer ability 27 . As observed, the surface electrostatic potential of Cu δ+ NCN was distinctly lower compared with the CuNCN and CuO, suggesting the favorable charge states for CO 2 RR. Moreover, the coordination mode of Cu with [NCN] 2− group in Cu δ+ NCN was analyzed by Fourier-transform infrared spectroscopy (FTIR), and the characteristic vibration peaks clearly proved that the [N–C≡N] 2− and [N=C=N] 2− coexisted in Cu δ+ NCN, which was different from CuNCN, only [N=C=N] 2− can be observed (Fig.  2f ). As revealed by our previous work, [N–C≡N] 2− anions prefers to bind to softer cations (e.g. Cu 1+ ) to create an electron delocalization of the Cu atoms in the framework 24 . In addition, the favorable proton and electron transfer nature of [NCN] 2− can accelerate the CO 2 RR. Consequently, the aforementioned results allow the reasonable structural determination of the Cu δ+ NCN nanosheets with coexisted isolated Cu 0 -Cu 1+ dual sites along with prime charge transfer characteristic.

CO 2 electroreduction performances

The electrochemical CO 2 RR experiments on Cu δ+ NCN were firstly evaluated in CO 2 -saturated 1.0 M KOH solution in a flow cell. Linear scanning voltammetry (LSV) curves (Fig.  3a ) showed that Cu δ+ NCN exhibited the lowest onset potentials as well as better reaction kinetics, especially in the presence of CO 2 , compared to CuNCN and CuO. Figure  3b showed the product selectivity of CO 2 RR on Cu δ+ NCN and contrast samples, and the electroreduction products were quantified by both gas chromatography and Nuclear Magnetic Resonance (NMR) spectroscopy (Supplementary Fig.  6 ). Cu δ+ NCN showed a prominent selectivity for C 2 H 4 (FE C2H4  > 50%) over the whole measured potentials from −1.0 to −1.6 V vs. RHE, it peaked at −1.4 V with a FE C2H4 of 72.6 ± 5.1% (Fig.  3b ), corresponding to a partial current density for C 2 H 4 ( j C2H4 ) of almost −400 mA cm −2 (Fig.  3c ). As a comparison, the CuNCN and CuO were less selective and its CO 2 RR catalysis yielded almost an equal amount of C 1 and C 2 products along with FE C2H4 in the range of 20-40% (Fig.  3b ). It is important to note that although the total catalytic current density of Cu δ+ NCN is lower than that of CuO in the range of −1.0 V to −1.3 V vs RHE, the j C2H4 on Cu δ+ NCN is significantly more advantageous due to its high FE C2H4 , and this advantage becomes even more pronounced as the potential increases (Fig.  3c ). Thereafter, a chronoamperometry study on Cu δ+ NCN catalyst over a 15 h span at −1.4 V vs. RHE showed an excellent stability in both current density ( ∼ 400 mA cm −2 ) and FE ( ∼ 70%) of CO 2 -to-C 2 H 4 (Fig.  3d ) In contrast, the FE C2H4 of CuNCN decreased from ∼ 40% to ∼ 18% after only 2 h under the same conditions (Supplementary Fig. 7 ). By comparing the FE of CO 2 to C 2 H 4 and corresponding j of Cu δ+ NCN with that for other reported excellent Cu-based electrocatalysts (Fig.  3e and Supplementary Tab.  4 ), the CO 2 RR performance of Cu δ+ NCN was found to locate in the best ranks of these Cu-based materials 8 , 14 , 17 , 18 , 19 , 28 , 29 , 30 , 31 , 32 , 33 , 34 .

a LSV curves of Cu δ+ NCN, CuNCN and CuO in a flow cell under CO 2 or Ar atmospheres. b FE of various products from Cu δ+ NCN, CuNCN and CuO at different potentials in a flow cell. c Ethylene partial current densities of Cu δ+ NCN, CuNCN and CuO at various potentials in a flow cell. d Performance of Cu δ+ NCN in a three-electrode flow cell to produce ethylene. e Comparison of the FE C2H4 and reduction current of Cu δ+ NCN with recently reported catalysts. f Schematic illustration of the APMA-MEA biphasic electrode system apparatus. g FE C2H4 of Cu δ+ NCN at various potentials in a biphasic electrode MEA system. h Stability performance of Cu δ+ NCN within the MEA to produce ethylene.

Subsequently, we studied the CO 2 RR catalysis over Cu δ+ NCN catalysts prepared with different reduction degree (Supplementary Fig.  8 ). For each catalyst, the FE and product distribution of each catalyst were measured, and the sample obtained with 5 mL of hydrazine displayed highest FE for C 2 H 4 (Fig.  3b ). In addition, we explored the hydrophilic and hydrophilic properties by contact angle measurements, and the electrochemical surface areas (ECSA) were also evaluated by the double-layer capacitance method: Cu δ+ NCN, CuNCN and CuO displayed similar hydrophilic ability and ECSA (Supplementary Fig.  9 & 10 ), suggesting that the hydrophobicity and surface area are not major contributors to the differences in the CO 2 RR performance.

Furthermore, the electrocatalytic CO 2 reduction of the Cu δ+ NCN catalyst was implemented in an anion-exchange membrane (AEM) + proton-exchange membrane (PEM) assembled membrane electrode assembly (MEA) system 35 , where the pure H 2 O was supplied as the anolyte to suppress carbonate formation and precipitation, as well as to diminish the solution resistance inherent in traditional flow cell (Fig.  3f ). The double membrane-based MEA electrolyzer heralds a substantial enhancement in electrocatalytic efficacy and current output for the reduction of CO 2 , culminating in a remarkable current density of 180 mA cm −2 at a cell voltage of 3.6 V (Fig.  3g ). Of particular note, this configuration sustains a high FE of 66.8% for the electrosynthesis of ethylene at 120 mA cm −2 . Furthermore, the Cu δ+ NCN catalyst demonstrates outstanding durability, enabling continuous operation for nearly 80 h at a cell voltage of 3.6 V (Fig.  3h ), thus exceeding the performance metrics of most catalysts documented to date (Supplementary Tab.  4 ).

Mechanism investigations

Studying the atomic structure-activity relationship of catalyst during the CO 2 RR process is crucial to reveal the intrinsic catalytic mechanism. To assess the chemical state of Cu in the Cu δ+ NCN under CO 2 RR (Fig.  4a ), operando XAS was performed (Supplementary Fig.  29 ), and the CuNCN was also measured for comparison (Fig.  4b ). No obvious structural changes were observed from the XANES at open circuit potential (OCP) for both Cu δ+ NCN and CuNCN (Fig.  4a, b ). When the potential was elevated every 0.3 V from the potential range of −0.7 to −1.6 V vs. RHE, drastic change took place in the sample of CuNCN, suggesting a potential-dependent process. In contrast, the Cu δ+ NCN displayed a slight change at the very beginning but negligible change with further increase of the applied potential. To make the comparison clearer, the variation of Cu valence state under the altered potential was plotted by comparing the first derivative energy position of the absorption edge (Fig. 4c , Supplementary Fig.  11 ). It could be clearly seen that at the initial potential of −0.7 V vs. RHE, the Cu δ+ NCN still maintained the Cu oxidation state that close to the OCP condition. Above this potential, the valence state of Cu stayed stable between +0.2 and +0.5 and almost remained with an average valence state of about +0.3. Previous research also reported that the [NCN] 2− group can safeguard the oxidation state of metals through a strong σ -donation effect and structural transformation, thereby maintaining the stability of the catalyst’s average valence state 25 . In comparison, a gradual shift of the absorption edge to low energy side in the CuNCN was observed, accompanied by the formation of more deoxidized Cu ions (valence state :0.5 to 1.5). This irreversible Cu nanocluster formation would lead to leach of [NCN] 2− group, which thus lead to the collapse of the open framework and loss of catalytic ability.

Operando XANES spectra of a Cu δ+ NCN and b CuNCN . c Fitted linear relationship between the energy position of the Cu K-edge in operando XANES spectra and the valence state of Cu. d Comparison of the EXAFS WTs of the Cu K-edge recorded during operando testing on Cu δ+ NCN. e Fourier-transformed k 3 -weighted EXAFS signals of the Cu K-edge recorded at different potentials on Cu δ+ NCN. f Changes of coordination number for the Cu–N, Cu–Cu and Cu–N/C coordination shells. g Changes of bond length for the Cu–N, Cu–Cu and Cu–N/C coordination shells. h Operando Raman spectra of Cu δ+ NCN. i Operando ATR-SEIRA spectra of Cu δ+ NCN, CuNCN and CuO.

The changes of the atomic local structure around Cu in Cu δ+ NCN during CO 2 RR were detected by Wavelet transforms for the k 3 - weighted Cu K-edge EXAFS (Fig.  4d ) and FT-EXAFS (Fig.  4e ) 36 , 37 , 38 . Similar to the FT-EXAFS signal collected on pristine sample, under open-circuit condition, FT-EXAFS data of Cu δ+ NCN showed one strong peak located at ~ 1.5 Å and a weak peak at ~ 2.2 Å. Considering that the coordination of N, C, and O with Cu is difficult to be distinguished in EXAFS, for the sake of Cu δ+ NCN structural determinism, we performed the fitting with these two peaks corresponding to the typical scattering features of the Cu-N/C/O and Cu-Cu coordination, respectively, and the fitted data match the experimental data very well (Supplementary Figs.  25 , 26 ). When applying a potential of −0.7 V vs. RHE, the scattering peak for Cu-N/C/O bond was on a general downward trend along with the increasing of Cu–Cu bond intensity as the potential decreased (Fig.  4d, e ). The conversion of CO 2 −to-C 2 H 4 reaction occurred simultaneously. Moreover, the intensity of bond pairs regarding Cu-N/C/O bond stabilized while the Cu–Cu bond slowly increased on subsequent potential decrease from −0.7 V to −1.3 V vs. RHE. In parallel, the FT-EXAFS fitting results of Cu δ+ NCN showed that the coordination number of Cu-N/C/O in the first shell stayed relatively stable nearby 1.5 along with increase of CN for Cu–Cu from 0.5 to 1.0 (Fig.  4f , Supplementary Fig.  25 & 26 and Table  S2 ). In contrast, the coordination number of Cu-N/C/O and Cu–Cu for CuNCN exhibited obvious decline, suggesting an irreversible Cu atom evolution from the [NCN] 2− framework (Supplementary Figs.  1 2– 14 , Supplementary Figs.  27 , 28 and Table  S3 ). Note that at the potential range of −0.7 V to −1.3 V vs. RHE, Cu δ+ NCN displayed stable and high FE C2H4 (> 50%) while FE C2H4 on CuNCN decreased gradually concurrently. In particular, for Cu δ+ NCN, the coordination number of Cu–Cu displayed a crude transfer to 1.6 once a larger negative voltage of −1.6 V vs. RHE was applied, which was accompanied by the appearance of a new Cu-N/C/O bond with coordination number of 1.4 and bond length 2.49 Å (Fig.  4g ). Combined with the optimal activity intervals and the excellent stability of Cu δ+ NCN in Fig. 3b, d , it can be judged that the coordination stability of Cu-N/C/O is crucial for Cu δ+ NCN to maintain its catalytic stability 39 . And When the voltage is further increased to −1.6 V or higher in a flow cell, a significant decrease in the coordination number of Cu-N/C/O on the surface of Cu δ+ NCN is observed. This is accompanied by a rapid increase in the coordination number of Cu-Cu, indicating that under the influence of voltage, in addition to the small amount of Cu clusters initially aggregated in a thermodynamically favorable manner, new Cu atoms have aggregated due to the breaking of some Cu-N/C/O bonds.

It is noteworthy that, at the same time, a new coordination attributed to Cu-N/C/O with a bond length of approximately 2.58 Å has emerged. This newly formed coordination will re-coordinate and stabilize these already formed Cu clusters, thereby ensuring the coexistence of Cu 0 and Cu 1+ on the surface. The coexistence of Cu 0 and Cu 1+ on the surface is highly consistent with the excellent stability of Cu δ+ NCN during the CO 2 RR process. We also investigated the physical phases as well as the surface chemical states of Cu δ+ NCN and CuNCN after undergoing CO 2 RR by XRD, XPS, SEM and EDS spectroscopy. Both XRD and SEM indicated that the phase and structure of Cu δ+ NCN almost preserved, with only a small peak for metallic state Cu ( ∼ 43.3 o ) observed (Supplementary Figs.  15 , 16 ), in good agreement with the increased CN of Cu–Cu bond in operando XAS. In contrast, besides of the huge morphology changes for CuNCN and CuO reference samples (Supplementary Fig.  16 ), the phase of CuNCN experienced the reduction to Cu 2 O and then to metallic Cu, while the CuO almost totally transformed to the metallic Cu (Supplementary Fig.  15 ). This observation was also proved by the EDS and related mapping results, where no N element can be detected in CuNCN, suggesting the continuous reducing of Cu + from the [NCN] 2− lead to the collapse of open framework (Supplementary Fig.  17 ), in accord with the decreased coordination number observed in XAS (Supplementary Fig.  13 ). The surface chemical states of Cu δ+ NCN and CuNCN after undergoing CO 2 RR for different times were further analyzed by XPS (Supplementary Fig.  18 ). The C-N coordination can be clearly observed on the surface of Cu δ+ NCN, whereas for CuNCN, C-N is almost not observed on the surface due to the loss of the [NCN] 2− moiety (Supplementary Fig.  18a, b ), which agrees with the results of EDS. The valence changes of Cu observed from operando XAS are also confirmed from Cu 2 p high-resolution XPS and Cu LMM spectra (Supplementary Fig.  18d, e ). When experiencing CO 2 RR for different reaction times, Cu reduction in CuNCN is clearly detected, whereas Cu δ+ NCN can maintain its surface chemical state even after a long time of reaction thanks to the protection of the oxidation state of strong σ -donation effect and structure transformation of [NCN] 2– 25 . The operando XAS together with post characterization study revealed an important phenomenon in our catalyst, that is the coexistence of stabilized Cu 0 -Cu 1+ dual sites by cyanamide framework under the reaction conditions and which can be stable maintained even during and after CO 2 RR.

To probe the catalytic intermediates and mechanism of CO 2 reduction by Cu δ+ NCN, operando electrochemical Raman (Fig.  4h ) and attenuated total reflection-surface enhanced infrared absorption (ATR-SEIRA) (Fig.  4i , Supplementary Figs.  19 , 20 ) experiments were conducted. As seen from the Raman spectra of Cu δ+ NCN in Fig.  4h , the peaks between ∼ 2100 and 2000 cm −1 attributed to the linearly bound *CO species were observed. The increased peak intensity and peak areas suggested a high *CO surface coverage and a strong *CO binding capability. As widely revealed by previous work, the promoted CO 2 -to-C 2+ efficiency basically depends on the coverage of surface *CO 40 . The high surface *CO would suppress HER and is vital for the subsequently C−C coupling, thereby enhancing the CO 2 -to-C 2 H 4 conversion 41 . These *CO signal bands were also detected in the operando ATR-SEIRA spectra around the 2100 cm −1 (Fig.  4i ), and both the peak intensity and area for Cu δ+ NCN increased much more obviously with the altered potentials compared to that of CuNCN and CuO. Simultaneously, it is readily observable that as the voltage increases, the adsorption of CO on the surface of Cu δ+ NCN is also further enhanced. This is consistent with the observation in Fig.  4f that the coordination number of Cu-Cu continues to increase with the application of voltage. The presence of Cu 0 accelerates the activation of CO 2 on the catalyst surface, ensuring that Cu 1+ sites can better adsorb CO, thereby further promoting the coupling of *CO-*CO. In parallel, a distinctive peak shoulder around 1530 cm −1 corresponding to the *COCO intermediate via *CO dimerization was observed in Cu δ+ NCN and increased accordingly with scanning to more negative potentials 42 . Simultaneously, a relatively weak character peak line for *COCHO (1440 cm −1 ), intermediate of hydrogenation of *CO dimer, was detected 43 . In contrast, these vital signals for CuNCN were much weaker, and almost negligible on CuO, which were consistent with the distinctive trend of C 2+ products formation rates on the three samples. Prominently, a shoulder peak around ∼ 2150 cm −1 presented when the potential was decreased, which corresponds to the C≡N vibration of the [N−C≡N] 2− moiety, taking responsibility for the electron transfer and stabilization of Cu 1+ . And importantly, by keeping the reaction time at the constant potential −1.6 V vs. RHE for 12 min (Supplementary Fig.  20 ), the signal for C≡N vibration was almost maintained, further revealing the robust structure of Cu δ+ NCN. As discussed above, the operando XAS study in conjunction with operando Raman and ATR-SEIRA analysis elucidated that the isolated Cu 0 -Cu 1+ dual sites stabilized by the cyanamide framework can enhance the coverage of surface *CO and facilitate the pathway of *CO dimerization to form *COCHO, thus improving the selectivity for C 2 H 4 during CO 2 RR.

DFT calculations

Theoretical investigations based on density functional theory (DFT) calculations were further adopted to gain insight into the CO 2 RR mechanism on Cu δ+ NCN. According to the fine structural analysis on pristine Cu δ+ NCN (Fig.  2 ), atomic isolated Cu 0 coordinated by the Cu-N in the Cu 2 NCN was confirmed. During the electrochemical reaction, the thermodynamically favorable aggregation of these Cu 0 lead to formation of few-atom Cu clusters, as observed by operando XAS (Fig.  4 a– g ). In light of this, a Cu 2 NCN coordinated Cu 0 -Cu 0 dual atoms model was used to represent the catalytic site to simplify the calculation (Supplementary Fig.  21 ). Considering that the Cu 0 atoms on the surface of Cu 2 NCN might be influenced by the paramagnetic of Cu 2 NCN, we also studied the effects of different spin states on the energy calculations prior to computing the energy of the Cu 0 sites. The results show that, in comparison with M Cu  = 0, higher spin of the Cu 0 atoms such as M Cu  = 1, 2, and 3 μB can significantly increase the total energies by 1.12 ~ 12.23 eV, indicating the M Cu  = 0 is the rational magnetic moment for Cu 0 atoms (Supplementary Fig.  22 ). The charge density difference was calculated for the surface copper and the second layer of copper using the Bader charge analysis method. Interestingly, the charge distribution between Cu atoms was charge-asymmetry as shown in Fig.  5a . The charge density of the Cu coordinated with the cyanamide (+0.77 e − ) was lower than that of the surface isolated metallic Cu atom (+0.83 e − ), proving the electron delocalization effect resulted from the [NCN] 2− . 3D charge density distribution model in Supplementary Fig.  23 further indicated the direct electron transfer from cyanamide framework in Cu δ+ NCN to surface metallic Cu atom, leading to a significant electron accumulation at surface Cu 0 sites and substantial electron depletion at the Cu 1+ sites, such electron distribution was vital for the stabilization of oxidized Cu 1+ and the preserve of surface neutral Cu 0 . We calculated the density of states projected on Cu 0 , Cu 1+ , and the coordinating N atoms. The intense charge transfer implies strong orbital hybridization and overlaps between the involved atoms, as shown below, the results show obvious hybridization and overlap between the Cu 0 3 d , Cu 1+ 3 d , and N 2 p orbitals, which indicate strong bindings between Cu 0 , Cu 1+ , and the coordinating N atoms, leading to stabilized Cu 0 and Cu 1+ . Meanwhile, for Cu 0 and Cu1 + in the surface and bulk phases, we calculated the vacancy formation energies of bulk Cu 1+ and surface Cu 0 in Cu δ+ NCN, respectively, and the results, as shown in Fig.  5b , show that the vacancy formation energy of Cu 1+ (4.79 eV), which is significantly higher than that of the surface Cu 0 (1.64 eV), which suggests that the bulk Cu 1+ is more stable than the surface Cu 0 . This result agreed well with the operando XAS observation, where the formation of few-atom Cu clusters was detected at high reduction potential, but still retained their native structure and demonstrate good stability due to the strong interaction of Cu-N with surface metallic Cu. We further investigated the dimerization kinetics of *CO to *OCCO on Cu surfaces with different oxidation states. As shown in Fig.  5c , when the catalyst surface is entirely composed of Cu 1+ , the dimerization of *CO on the surface requires overcoming a high activation energy barrier (1.55 eV) to form the transient state (TS1). When the catalyst surface is entirely composed of Cu 0 , the barrier for TS1 is reduced to 1.12 eV. However, on the surface of Cu δ+ NCN (coexistence of Cu 0 /Cu 1+ ), the barrier for TS1 is further reduced to 0.86 eV. This clearly demonstrates the importance of the Cu 0 /Cu 1+ environment maintained by CuNCN for the efficient production of C 2 products 44 , 45 .

a Charge density section plots of surface Cu atoms and second layer Cu atoms of Cu δ+ NCN. b Vacancy formation energy of surface Cu 0 and bulk phase Cu 1+ . c Energy barriers of *CO-*CO coupling·on the Cu δ+ NCN surface, Cu (111) surface, and Cu 2 O (110) surface at U = −0.8 V. The corresponding transition state structures are shown in the insets. d Free energy profiles of the involved reaction intermediates under U = −0.8 V, the corresponding kinetic barriers of key reaction steps are provided in the brackets, the atomic structures of the transition states are shown in the insets.

Mechanisms for the generation of C 2 H 4 product have been widely explored and many different reaction pathways have been proposed 46 , 47 . The *CO mechanism was preferred for Cu δ+ NCN than the *OCHO mechanisms due to the continuous generation of the CO product with the formation of C 2 H 4 in the testing window as shown in Fig.  3b . By combing the results of operando ATR-SEIRA analysis (Fig.  4i ), the hydrogenated *CO dimer (*COCHO) formed a key C 2 intermediate *CHCOH after a sequence of proton and electron transfer steps 48 . As a later key stage of the C 2 pathway, the hydrogenation of *CHCOH can lead to branching pathways to either ethylene or ethanol. On the basis of reaction free energies (ΔG) calculated at constant potential of −0.8 V in Fig.  5d , the *CHC pathway representing the formation of ethylene was proved to be more energetically favorable with a free energy change of -1.02 eV, much lower than that for *CHCHOH (ΔG = -0.68 eV), the typical pathway for ethanol. We further studied the kinetic barrier of this step, the barrier of *CHCOH → *CHCHOH is 1.07 eV, while the barrier of *CHCOH → *CHC is only 0.64 eV, indicating the formation of ethylene via *CHC intermediate is more favorable than the formation of ethanol in kinetics, consistent with our experimental results. Together, the reaction pathway of CO 2 to C 2 H 4 on Cu δ+ NCN was proposed as: CO 2  → *CO → *COCO → *COCHO → *CHCOH → *CHC → C 2 H 4 based on the both operando characterization and theoretical calculations (Fig.  5d and Supplementary Tab.  5 ).

We have proposed a cyanamide coordinated isolated Cu framework with balanced metallic Cu (Cu 0 ) and delocalized Cu (Cu 1+ ) sites acts as an efficient electrocatalyst for CO 2 -to-C 2 H 4 reduction. These isolated neutral Cu 0 atoms in Cu δ+ NCN enhanced the surface *CO by activating CO 2 , while the electron delocalized Cu 1+ lead to boost of C–C coupling by offering a lower reaction free energy for *CHC formation and high selectivity for C 2 H 4 . The tangible Cu δ+ NCN catalyst exhibited one of the highest reported CO 2 RR selectivity towards C 2 H 4 with Faradaic efficiency of 77.7% at the partial current density of 400 mA cm −2 , togethering with stable reduction capability of CO 2 -to-C 2 H 4 for almost 80 h in a MEA-based electrolyser. Our work not only suggests an ingenious strategy to selective to stabilize the valence state of Cu to realize the product selectivity of CO 2 RR, but it also introduces the specific coordination structures in designing CO 2 RR materials for the electrosynthesis of high value-added products.

Copper chloride, copper nitrate, sodium hydroxide, cyanamide, Iridium (IV) Oxide and hydrazine were purchased from Adamas. Anion-exchange membrane (Fumasep-FAA-3-50) and anion-exchange membrane solution was purchased from Fumatech, German. Proton exchange membrane (N212) and Nafion perfluorinated resin (5 wt%) were purchased from DuPont, USA. All chemicals were used directly from the manufacturer without further purification.

Synthesis of Cu δ+ NCN

The procedure for the fabrication of Cu δ+ NCN was modified based on methodologies delineated in prior literature 24 . At room temperature, 426.6 mg of copper chloride was dissolved in 45 mL deionized water. Next, 2.5 mL of 3.5 M sodium hydroxide and 3 mL of 2 M cyanamide were added in order. The mixture was stirred for 3 minutes, then 5 mL of hydrazine was quickly poured in. After 2 h of reaction, the mixture was centrifuged, washed with deionized water, centrifuged again, and the final product was obtained by freeze-drying.

Synthesis of CuNCN

CuNCN was synthesized in a similar manner to Cu δ+ NCN, except that hydrazine was not added during the synthesis.

Synthesis of CuO

This approach is in accordance with the methodologies delineated in prior studies 49 . Copper Oxide (CuO) were synthesized utilizing the hydrothermal technique, employing copper (II) nitrate (Cu(NO₃)₂) as the precursor. An aqueous sodium hydroxide solution with a molarity of three moles per liter (3 M, 2 mL) was incrementally introduced into a copper (II) nitrate solution of one mole per liter (1 M, 2 mL). The resultant mixture was subjected to vigorous stirring for a duration of one hour to ensure homogeneity. Subsequently, the mixture was subjected to a thermal treatment at a temperature of 120 °C for 4 h. Upon completion of the heating phase, the system was allowed to equilibrate to room temperature. The final stage encompassed a series of purification steps including centrifugation, meticulous washing, and a drying process.

Materials characterization

The surface textures and elemental distribution of the catalysts were meticulously delineated utilizing a field-emission scanning electron microscope (FE-SEM, Zeiss Gemini 300). The assessment of elemental composition and quantification was conducted through an Energy Dispersive X-ray Spectroscopy (EDS, JEOL-2010) apparatus integrally connected to the FE-SEM. Scanning transmission electron microscopy (STEM) images alongside energy-dispersive X-ray spectroscopy (EDS) mappings were procured using a JEOL ARM300 microscope. This state-of-the-art instrument boasts the capability of capturing ultrahigh-resolution STEM images with an exceptional spatial resolution of 63 picometers. The microscope is outfitted with a dual spherical aberration (CS) corrector, enhancing image clarity and precision. Additionally, it is equipped with an advanced X-ray energy dispersive spectrometer (JED-2300 Series), which incorporates a pair of 158 mm 2 solid-state detectors (SSD) for superior spectral sensitivity and precise elemental analysis. To decipher the crystalline architecture of the samples, X-ray diffraction (XRD) profiles were acquired using a Bruker D8-Advance X-ray diffractometer, employing Cu- Kα radiation. The catalyst samples were aerated and methodically surveyed across a range of 5 to 80 degrees at a rate of 5 degrees per minute. The KPFM characterization was carried out with atomic force microscope (nanoIR2-FS). Inductively coupled plasma atomic emission spectroscopy (ICP-OES) was performed on an Agilent 5110 ICP spectrometer. Analysis of the valence states of the elemental constituents was executed via X-ray photoelectron spectroscopy (XPS, Thermo Scientific K-Alpha). Prior to engaging in curve fitting and background attenuation, a standardization of the XPS spectra was performed referencing the C 1 s peak. The Fourier-transform infrared (FTIR) spectra were captured using a Thermo Scientific Nicolet iS20 spectrophotometer; each sample was meticulously prepared by compressing it into a pellet with KBr powder.

Electrochemical measurement

The assessment of CO 2 reduction reaction (CO 2 RR) efficacy was meticulously conducted within both a flow cell and a membrane electrode assembly (MEA) electrolytic cell. apparatus.

Within the flow cell measurements, an electrolytic solution of 1 M KOH, exhibiting a pH of 13.8, was utilized as both the anolyte and catholyte. The gaseous environments perfusing the cathodic compartment were composed of CO 2 and Argon, tailored to the specific exigencies of the reaction conditions. The trifecta of electrodes comprised a gas-diffusion layer measuring 1 cm by 3 cm, a platinum sheet of identical dimensions, and a silver/silver chloride (Ag/AgCl) reference electrode immersed in saturated KCl, each meticulously arranged, with the active operative surface area precisely defined at 1 cm 2 . The catalyst loading on the cathode is 0.7 mg cm − 2 . An anion exchange membrane of type FAA-3-50 provided a discrete partition between the cathode and anode chambers. The regulation of gaseous flow was achieved with a mass flowmeter, maintaining a rate of 40 mL min −1 , while a peristaltic pump assiduously controlled the electrolyte flow at a rate of 10 mL min − 1 . The calibration of potentialities was scrupulously performed in reference to the reversible hydrogen electrode (RHE), utilizing the equation: E (vs. RHE) = E (vs Ag/AgCl) + 0.197 V + (0.0592 × pH). Linear sweep voltammetry (LSV) was executed within the gas diffusion cell at a scanning velocity of 10 mV s − 1 , traversing a potential range from 0 to −1.7 V versus RHE. The electrochemical active surface area (ECSA) of the catalyst was appraised by gauging electrochemical capacitance over scanning velocities ranging from 20 to 100 mV s −1 , with increments of 20 mV s − 1 , within a non-Faradaic potential window. The electrochemical double-layer capacitance (C dl ) of the specimen was estimated by the differential current (Δ j ) at the varying scanning rates. All voltages were not subjected to iR compensation.

Within the MEA electrolytic cell measurements, using a home-made flow channel plate as a jig, a Nafion N212 membrane as the PEM, and Fumasep-FAA-3-50 as the AEM, an APMA-MEA system was constructed. The anode catalyst employed was iridium dioxide with a loading of 2 mg cm − 2 , which was applied to the pre-treated PEM through the CCM (Catalyst Coated Membrane) method and thermally pressed before use. The anode gas diffusion layer utilized a platinum-coated titanium mesh. The cathode catalyst was Cu δ+ NCN with a loading of 2 mg cm −2 , which was spray-coated onto YLS-30T carbon paper using the CCS (Catalyst Coated Substrate) method and was not thermally pressed. The anolyte is deionized water with a flow rate controlled at 30 milliliters per minute, while the cathode gas is humidified with deionized water at 50 °C before entering the cathode chamber, with its flow rate controlled at 30 standard cubic centimeters per minute (sccm). The MEA testing is performed using chronoamperometry. All electrochemical tests were conducted at room temperature.

Products analysis

The electrochemical reduction of CO 2 was meticulously conducted at ambient temperature, employing a saturated 1 M KOH electrolytic solution across a potential range of −0.8 V to −1.6 V with respect to the reversible hydrogen electrode (RHE). The cathodic electrolysis was methodically sustained for a duration of 20 minutes at each discrete potential setting. Concurrently, oxygen evolution at the anode was expelled along with the electrolyte via the methodical action of a peristaltic pump. The identification and quantification of gaseous byproducts emanating from the cathodic domain of the electrocatalytic CO 2 reduction were assiduously monitored through online gas chromatography equipped with both a flame ionization detector (FID) and a thermal conductivity detector (TCD) (Model A91 Plus, Panna Instruments, China), with analyses conducted at five-minute intervals.

Throughout the CO 2 reduction reaction, the gaseous outputs from both the flow cell and the MEA electrolytic cell were quantitatively ascertained via online chromatographic analysis on a bi-temporal basis of five minutes, utilizing the dual-detection system.

The faradaic efficiency (FE) of the gaseous products was calculated using the equation:

where ( \(v\) ) denotes the volumetric flow of CO 2 through the cathodic chamber (volume per second), ( \(x\) ) represents the product concentration as determined from a 1 ml sample loop calibrated against a standard gas via online GC, ( \(N\) ) is the number of electrons transferred in the reduction process, ( \(F\) ) signifies the Faraday constant (96,485 C mol − 1 ), and ( \(j\) ) is the current density at the given moment.

Post-electrolysis, the cathodic liquid was diligently collected and subjected to a 400 MHz nuclear magnetic resonance (NMR) spectrometer for quantitation of the aqueous products. Following a 20-minute CO 2 RR session at the specified potential, the electrolyte was gathered, and a 500 μL aliquot was mixed with 100 μL of a 10 mM DMSO solution and 100 μL of D 2 O for diagnostic analysis of the liquid product profile via a 400 MHz 1 H-NMR spectrometer. To construct calibration curves, a series of liquid-phase products standards in DMSO and D 2 O were assayed using NMR. Within the one-dimensional ¹H NMR spectra, the water signal was attentively suppressed, placing the DMSO and liquid-phase products proton resonances, respectively. The liquid-phase products concentration within the electrolyte was deduced from the standard curve.

Faradaic efficiency of the liquid-phase products was determined by the equation:

where ( \(V\) ) is the volume of the cathode electrolyte, ( \(x\) ) is the concentration of liquid-phase products, ( \(N\) ) is the number of electrons involved in the reduction process, ( \(F\) ) is the Faraday constant (96,485 C mol −1 ), and ( \({Q}_{{total}}\) ) is calculated by integrating the current over time.

Operando Raman spectroscopy

Operando Raman spectroscopy analyses were performed using a Horiba LabRAM HR Evolution system. The experimental arrangement for the electrode mirrored that of the antecedent electrochemical tests, with the modification of the electrolyte to a 0.1 M KHCO 3 solution. This modification was intended to mitigate the absorption of CO 2 by KOH. Spectral acquisition was performed under 532 nm laser excitation, operated at 10% of the laser potential intensity, and the exposure duration was set to 20 s. Open circuit voltage Raman spectra is the spectra collected by the sample directly immersed in 0.1 M KHCO 3 . Operando Raman spectra were collected using chronoamperometry at −0.3 - −0.8 V vs. RHE without iR drop compensation.

Operando ATR-SEIRA spectroscopy

The catalytic layer was applied onto a chemically prepared Au film situated atop a Si ATR prism, with subsequent ATR-SEIRAS assessments conducted using a PerkinElmer Spectrum FTIR spectrometer, integrated with a MCT detector. A spectral resolution of 4 cm − 1 was selected. Spectral acquisition was conducted within the wavenumber range of 400 to 4000 cm − 1 , with the number of scans set to four. During the testing process, Au film was utilized as the working electrode onto which the ink was drop-cast and dried prior to testing. A platinum slice served as the counter electrode, and Ag/AgCl electrode was used as the reference in a three-electrode setup. Electrolyte 0.5 M KHCO 3 was employed for the electrochemical measurements. Chronoamperometry was the technique used for the electrochemical test, with the test voltage range spanning from −0.1 V to −1.5 V vs. RHE. Spectral data were collected twice after a reaction time of 30 s at each potential. Finally, spectral data were continuously acquired for 12 min at a potential of −1.6 V vs. RHE.

Operando XAFS

The Cu K-edge XAFS spectra were measured at BL17B1 beamline of Shanghai Synchrotron Radiation Facility (SSRF), China. The storage ring of the SSRF were operated at 2.5 GeV with a maximum electron current of 250 mA. Operando XAFS measurements were performed in a homemade cell (Supplementary Fig.  29 ). Catalyst-loaded carbon paper as working electrode with polyimide film on the back side and then glued to the surface of the operando electrolytic cell, with the catalyst in direct contact with the electrolyte. A 0.5 M KHCO 3 solution was used as the electrolyte. All X-ray was monochromatized by a Si (111) double-crystal monochromator with the energy calibrated using Cu foils.

XAFS analysis and results

The acquired EXAFS data were processed according to the standard procedures using the ATHENA module of Demeter software packages 50 .

The EXAFS spectra were processed by first removing the post-edge background from the total absorption and then normalizing it relative to the edge-jump step. Afterward, the χ(k) data were Fourier transformed into real (R) space using a Hanning window with a width of dk = 1.0 Å −1 to distinguish the EXAFS contributions from various coordination shells. To extract the quantitative structural parameters surrounding the central atoms, least-squares curve fitting was carried out using the ARTEMIS module within the Demeter software suite 50 .

The following EXAFS equation was used 51

the theoretical calculations included scattering amplitudes, phase shifts, and photoelectron mean free paths for all considered paths. The amplitude reduction factor is represented by S 0 2 , while F j (k) denotes the effective curved-wave backscattering amplitude. N j represents the number of neighboring atoms in the j th atomic shell, and R j is the distance between the X-ray absorbing central atom and the atoms in the j th atomic shell. The mean free path, denoted as λ, is expressed in Å. The phase shift, ϕ j (k), encompasses both the individual shell phase shifts and the total phase shift for the central atom. The Debye-Waller factor, σ j , characterizes the variation in distances around the average R j within the j th shell. The functions F j (k), λ, and ϕ j (k) were computed using the ab initio software FEFF9. Further details on the EXAFS simulations are provided below.

All fits were performed in the R space with k -weight of 3 while phase correction was also applied in the first coordination shell to make R value close to the physical interatomic distance between the absorber and shell scatterer. The coordination numbers of model samples were fixed as the nominal values. The obtained S 0 2 was fixed in the subsequent fitting. While the internal atomic distances R, Debye-Waller factor σ 2 , and the edge-energy shift Δ were allowed to run freely. The detailed analysis results are illustrated in Supplementary Tables 2, 3 .

For Wavelet Transform analysis, the χ(k) exported from Athena was imported into the Hama Fortran code. The parameters were listed as follow: R range, 1–4 Å, k range, 0–15 Å −1 for samples; k weight, 3; and Morlet function with κ = 10, σ = 1 was used as the mother wavelet to provide the overall distribution.

Density functional theory computation

Density functional theory (DFT) investigations were carried out using the Vienna ab initio simulation package (VASP). The interaction between ions and electrons under the frozen-core approximation was described employing the projector augmented wave (PAW) method 52 . Kohn-Sham valence states were expanded in a plane-wave basis set with a cut-off energy of 450 eV. Spin-polarized calculations utilized the Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional within the generalized gradient approximation (GGA) 53 , 54 . The Brillouin zone integration employed a Monkhorst-Pack mesh of 3 × 3 × 1. To separate periodic images, a 15 Å vacuum was added. The atomic structures were relaxed until the forces were less than 0.03 eV Å −1 . For the implicit solution model, VASPsol was implemented to balance the net electronic charges introduced by the constant-potential method 55 . The relative permittivity was set to 78.4, and a linearized Poisson–Boltzmann model with a Debye length of 3.0 Å was employed to mimic the compensating charge. In addition, we obtained the charge values using the Bader charge analysis method.

Constant-potential method for obtaining the potential-dependent grand canonical energies

In the constant-potential calculations, the structures and work functions of the involved reaction intermediates were fully optimized to account for the effect of an applied potential. The optimization method we utilized is developed by Duan et al. 56 . The work functions of the reaction intermediates are related to the applied potential by referencing them to Φ SHE  = − 4.6 eV, which is the work function of the standard hydrogen electrode (SHE).

Free energy calculation method under constant potentials

In this work, the grand free energy changes (ΔG) of the key CO 2 RR steps under a constant potential (U) were evaluated by Eq. ( 4 ):

where ΔZPE is the zero-point energy change, ΔG U PCET is the free energy contribution of proton-coupled electron transfer (PCET) at electrode potential U. ΔG pH  = 2.303 × k B T × pH (or 0.06 × pH) eV. The entropy change is denoted as ΔS, while C p signifies the constant-pressure heat capacity. The entropy and the integration term are obtained through the vibrational energy calculations of the CO 2 RR intermediates.

In the above equation, E(U) is defined as a grand canonical energy of the system:

where E DFT is the energy calculated from DFT, Δn CPS is the number of electrons added or removed from the system, which is determined by the constant-potential method. Φ SHE is the work function of the standard hydrogen electrode, SHE (−4.6 eV), and V sol is the potential deep in the solution.

Formation energy of a Cu vacancy

The surface Cu 0 and bulk phase Cu 1+ vacancy formation energies are defined as:

where E vac is total energy of the structure with a Cu vacancy, E Cu is the energy of a single Cu atom, E tot is the total energy of the pristine structure without any defects. In this work the energy of single Cu atom refers to an isolated Cu atom in vacuum.

Data availability

The data generated in this study are provided in the Supplementary Information and are available from the authors upon request.  Source data are provided with this paper.

Fang, W. et al. Durable CO 2 conversion in the proton-exchange membrane system. Nature 626 , 86–91 (2024).

Article   ADS   PubMed   Google Scholar  

Wang, J. et al. Spatially and temporally understanding dynamic solid-electrolyte interfaces in carbon dioxide electroreduction. Chem. Soc. Rev. 52 , 5013–5050 (2023).

Article   PubMed   Google Scholar  

Woldu, A. R., Huang, Z., Zhao, P., Hu, L. & Astruc, D. Electrochemical CO 2 reduction (CO 2 RR) to multi-carbon products over copper-based catalysts. Coord. Chem. Rev. 454 , 214340 (2022).

Article   Google Scholar  

Zhang, H., Gao, J., Raciti, D. & Hall, A. S. Promoting Cu-catalysed CO 2 electroreduction to multicarbon products by tuning the activity of H 2 O. Nat. Catal. 6 , 807–817 (2023).

Chen, Y. et al. Efficient multicarbon formation in acidic CO 2 reduction via tandem electrocatalysis. Nat. Nanotechnol. 19 , 311–318 (2023).

Fang, W. et al. Low-coordination Nanocrystalline Copper-based Catalysts through Theory-guided Electrochemical Restructuring for Selective CO 2 Reduction to Ethylene. Angew. Chem. Int. Ed. 63 , e202319936 (2024).

Huang, J. E. et al. CO 2 electrolysis to multicarbon products in strong acid. Science 372 , 1074–1078 (2021).

Zhong, M. et al. Accelerated discovery of CO 2 electrocatalysts using active machine learning. Nature 581 , 178–183 (2020).

Amirbeigiarab, R. et al. Atomic-scale surface restructuring of copper electrodes under CO 2 electroreduction conditions. Nat. Catal. 6 , 837–846 (2023).

Gao, W., Xu, Y., Fu, L., Chang, X. & Xu, B. Experimental evidence of distinct sites for CO 2 -to-CO and CO conversion on Cu in the electrochemical CO 2 reduction reaction. Nat. Catal. 6 , 885–894 (2023).

Wang, X. et al. Morphology and mechanism of highly selective Cu (II) oxide nanosheet catalysts for carbon dioxide electroreduction. Nat. Commun. 12 , 794 (2021).

Article   ADS   PubMed   PubMed Central   Google Scholar  

De Luna, P. et al. Catalyst electro-redeposition controls morphology and oxidation state for selective carbon dioxide reduction. Nat. Catal. 1 , 103–110 (2018).

Wang, J. et al. Strong Correlation between the Dynamic Chemical State and Product Profile of Carbon Dioxide Electroreduction. ACS Appl. Mater. Interfaces 14 , 22681–22696 (2022).

Ma, W. et al. Electrocatalytic reduction of CO 2 to ethylene and ethanol through hydrogen-assisted C–C coupling over fluorine-modified copper. Nat. Catal. 3 , 478–487 (2020).

Feng, J. et al. Improving CO 2 -to-C 2+ Product Electroreduction Efficiency via Atomic Lanthanide Dopant-Induced Tensile-Strained CuO x Catalysts. J. Am. Chem. Soc. 145 , 9857–9866 (2023).

Wang, J., Tan, H. Y., Zhu, Y., Chu, H. & Chen, H. M. Linking the Dynamic Chemical State of Catalysts with the Product Profile of Electrocatalytic CO 2 Reduction. Angew. Chem. Int. Ed. 60 , 17254–17267 (2021).

Liu, M. et al. Potential Alignment in Tandem Catalysts Enhances CO 2 -to-C 2 H 4 Conversion Efficiencies. J. Am. Chem. Soc. 146 , 468–475 (2024).

Wen, C. F. et al. Highly Ethylene‐Selective Electrocatalytic CO 2 Reduction Enabled by Isolated Cu- S Motifs in Metal–Organic Framework Based Precatalysts. Angew. Chem. Int. Ed. 61 , e202111700 (2022).

Article   ADS   Google Scholar  

Zhang, X. Y. et al. Direct OC-CHO coupling towards highly C 2+ products selective electroreduction over stable Cu 0 /Cu 2+ interface. Nat. Commun. 14 , 7681 (2023).

Lin, S.-C. et al. Operando time-resolved X-ray absorption spectroscopy reveals the chemical nature enabling highly selective CO 2 reduction. Nat. Commun. 11 , 3525 (2020).

Su, X. et al. Complementary operando spectroscopy identification of in-situ generated metastable charge-asymmetry Cu 2 -CuN 3 clusters for CO 2 reduction to ethanol. Nat. Commun. 13 , 1322 (2022).

Xu, H. et al. Highly selective electrocatalytic CO 2 reduction to ethanol by metallic clusters dynamically formed from atomically dispersed copper. Nat. Energy 5 , 623–632 (2020).

Jia, B., Sun, D., Zhao, W. & Huang, F. Metal cyanamides: Open-framework structure and energy conversion/storage applications. J. Energy Chem. 61 , 347–367 (2021).

Kong, S. et al. Delocalization state-induced selective bond breaking for efficient methanol electrosynthesis from CO 2 . Nat. Catal. 6 , 6–15 (2023).

Jia, B. et al. Indium Cyanamide for Industrial-Grade CO 2 Electroreduction to Formic Acid. J. Am. Chem. Soc. 145 , 14101–14111 (2023).

Article   PubMed   PubMed Central   Google Scholar  

Wang, J. et al. In situ X-ray spectroscopies beyond conventional X-ray absorption spectroscopy on deciphering dynamic configuration of electrocatalysts. Nat. Commun. 14 , 6576 (2023).

Wu, Z.-Z. et al. Identification of Cu (100)/Cu (111) interfaces as superior active sites for CO dimerization during CO 2 electroreduction. J. Am. Chem. Soc. 144 , 259–269 (2021).

Chen, X. et al. Electrochemical CO 2 -to-ethylene conversion on polyamine-incorporated Cu electrodes. Nat. Catal. 4 , 20–27 (2021).

Lu, Y. F. et al. Predesign of catalytically active sites via stable coordination cluster model system for electroreduction of CO 2 to ethylene. Angew. Chem. Int. Ed. 60 , 26210–26217 (2021).

Chen, Z. et al. Grain-boundary-rich copper for efficient solar-driven electrochemical CO 2 reduction to ethylene and ethanol. J. Am. Chem. Soc. 142 , 6878–6883 (2020).

Qiu, X.-F., Zhu, H.-L., Huang, J.-R., Liao, P.-Q. & Chen, X.-M. Highly selective CO 2 electroreduction to C 2 H 4 using a metal–organic framework with dual active sites. J. Am. Chem. Soc. 143 , 7242–7246 (2021).

Choi, C. et al. Highly active and stable stepped Cu surface for enhanced electrochemical CO 2 reduction to C 2 H 4 . Nat. Catal. 3 , 804–812 (2020).

Kim, J. et al. Vitamin C-induced CO 2 capture enables high-rate ethylene production in CO 2 electroreduction. Nat. Commun. 15 , 192 (2024).

Xie, M. et al. Fast Screening for Copper-Based Bimetallic Electrocatalysts: Efficient Electrocatalytic Reduction of CO 2 to C 2+ Products on Magnesium-Modified Copper. Angew. Chem. Int. Ed. 61 , e202213423 (2022).

She, X. et al. Pure-water-fed, electrocatalytic CO 2 reduction to ethylene beyond 1,000 h stability at 10 A. Nat. Energy 9 , 81–91 (2024).

Chang, C. J. et al. Dynamic Reoxidation/Reduction-Driven Atomic Interdiffusion for Highly Selective CO 2 Reduction toward Methane. J. Am. Chem. Soc. 142 , 12119–12132 (2020).

Hsu, C.-S. et al. Activating dynamic atomic-configuration for single-site electrocatalyst in electrochemical CO 2 reduction. Nat. Commun. 14 , 5245 (2023).

Tan, H. Y. et al. Reversibly Adapting Configuration in Atomic Catalysts Enables Efficient Oxygen Electroreduction. J. Am. Chem. Soc. 145 , 27054–27066 (2023).

Yang, D., Zuo, S., Yang, H., Zhou, Y. & Wang, X. Freestanding millimeter‐scale porphyrin‐based monoatomic layers with 0.28 nm thickness for CO 2 electrocatalysis. Angew. Chem. Int. Ed. 59 , 18954–18959 (2020).

Wang, X. et al. Mechanistic reaction pathways of enhanced ethylene yields during electroreduction of CO 2 –CO co-feeds on Cu and Cu-tandem electrocatalysts. Nat. Nanotechnol. 14 , 1063–1070 (2019).

Li, J. et al. Enhanced multi-carbon alcohol electroproduction from CO via modulated hydrogen adsorption. Nat. Commun. 11 , 3685 (2020).

Kim, Y. et al. Time-resolved observation of C–C coupling intermediates on Cu electrodes for selective electrochemical CO 2 reduction. Energy Environ. Sci. 13 , 4301–4311 (2020).

Delmo, E. P. et al. In Situ Infrared Spectroscopic Evidence of Enhanced Electrochemical CO 2 Reduction and C-C Coupling on Oxide-Derived Copper. J. Am. Chem. Soc. 146 , 1935–1945 (2024).

Zhang, J. et al. Grain Boundary-Derived Cu + /Cu 0 Interfaces in CuO Nanosheets for Low Overpotential Carbon Dioxide Electroreduction to Ethylene. Adv. Sci. 9 , e2200454 (2022).

Yuan, X. et al. Controllable Cu 0 -Cu + Sites for Electrocatalytic Reduction of Carbon Dioxide. Angew. Chem. Int. Ed. 60 , 15344–15347 (2021).

Kastlunger, G., Heenen, H. H. & Govindarajan, N. Combining First-Principles Kinetics and Experimental Data to Establish Guidelines for Product Selectivity in Electrochemical CO 2 Reduction. ACS Catal. 13 , 5062–5072 (2023).

Li, X., Wu, X., Lv, X., Wang, J. & Wu, H. B. Recent advances in metal-based electrocatalysts with hetero-interfaces for CO 2 reduction reaction. Chem. Catal. 2 , 262–291 (2022).

Li, Y. C. et al. Binding Site Diversity Promotes CO 2 Electroreduction to Ethanol. J. Am. Chem. Soc. 141 , 8584–8591 (2019).

Wang, P. et al. Sub-1 nm Cu 2 O Nanosheets for the Electrochemical CO 2 Reduction and Valence State–Activity Relationship. J. Am. Chem. Soc. 145 , 26133–26143 (2023).

Ravel, B. & Newville, M. ATHENA, ARTEMIS, HEPHAESTUS: data analysis for X-ray absorption spectroscopy using IFEFFIT. J. Synchrotron Radiat. 12 , 537–541 (2005).

Newville, M. EXAFS analysis using FEFF and FEFFIT. J. Synchrotron Radiat. 8 , 96–100 (2001).

Blöchl, P. E. Projector augmented-wave method. Phys. Rev. B 50 , 17953 (1994).

Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77 , 3865 (1996).

Hammer, B., Hansen, L. B. & Nørskov, J. K. Improved adsorption energetics within density-functional theory using revised Perdew-Burke-Ernzerhof functionals. Phys. Rev. B 59 , 7413–7421 (1999).

Mathew, K., Kolluru, V. S. C., Mula, S., Steinmann, S. N. & Hennig, R. G. Implicit self-consistent electrolyte model in plane-wave density-functional theory. J. Chem. Phys. 151 , 234101 (2019).

Duan, Z. & Xiao, P. Simulation of Potential-Dependent Activation Energies in Electrocatalysis: Mechanism of O–O Bond Formation on RuO 2 . J. Phys. Chem. C. 125 , 15243–15250 (2021).

Download references

Acknowledgements

This project is funded by financial support from the National Natural Science Foundation of China (22279159, YY), Natural Science Foundation of Shanghai (22ZR1471900, YY) and Shanghai Rising-Star Program (22QA1410300, YY). We also thank BL17B1 and BL 20U station at Shanghai Synchrotron Radiation Facility (SSRF) for the help in characterizations and supercomputing Facilities were provided by Hefei Advanced Computing Center.

Author information

These authors contributed equally: Kaihang Yue, Yanyang Qin.

Authors and Affiliations

State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, China

Kaihang Yue, Honghao Huang, Zhuoran Lv, Fuqiang Huang & Ya Yan

Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China

Kaihang Yue & Ya Yan

School of Chemistry, Xi’an Jiaotong University, Xi’an, 710049, China

Yanyang Qin & Yaqiong Su

State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China

Zhuoran Lv, Mingzhi Cai & Fuqiang Huang

State Key Laboratory of Rare Earth Materials Chemistry and Applications College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China

Mingzhi Cai

You can also search for this author in PubMed   Google Scholar

Contributions

Y.Y. and F.Q.H. conceived the idea of the project. K.H.Y., H.H.H. and Y.Y. designed and carried out the electrochemical experiments, Y.Y.Q. carried out the DFT calculations, Y.Q.S. and Y.Y. supervised and advised the DFT calculations, K.H.Y. and Y.Y. performed and discussed XAS characterization, Z.R.L. and M.Z.C. contributed to result discussion and data analysis, F.Q.H. commented and revised the manuscript. Y.Y. and K.H.Y. wrote and revised the manuscript. All the authors discussed the results and assisted with the manuscript preparation.

Corresponding authors

Correspondence to Yaqiong Su , Fuqiang Huang or Ya Yan .

Ethics declarations

Competing interests.

The authors declare no competing interests.

Peer review

Peer review information.

Nature Communications thanks Biaobiao Zhang, Sze-Chun Tsang and the other, anonymous, reviewers for their contribution to the peer review of this work. A peer review file is available.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary information, peer review file, source data, source data, rights and permissions.

Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/ .

Reprints and permissions

About this article

Cite this article.

Yue, K., Qin, Y., Huang, H. et al. Stabilized Cu 0 -Cu 1+ dual sites in a cyanamide framework for selective CO 2 electroreduction to ethylene. Nat Commun 15 , 7820 (2024). https://doi.org/10.1038/s41467-024-52022-0

Download citation

Received : 07 February 2024

Accepted : 22 August 2024

Published : 07 September 2024

DOI : https://doi.org/10.1038/s41467-024-52022-0

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

By submitting a comment you agree to abide by our Terms and Community Guidelines . If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Quick links

• Explore articles by subject
• Guide to authors
• Editorial policies

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.