KR20190009686A - Particle including atomic-scale channel, method of preparing the same, and catalyst including the same - Google Patents

Abstract

The present invention relates to a particle including at least one atomic-scale channel formed on a surface of the particle or on a surface and inside of the particle; a catalyst including the particle, particularly a catalyst for efficient and selective electrochemical conversion of carbon dioxide into high value-added C_(2+) fuel; and a method of preparing the particle. More specifically, the present invention relates to design and construction for an atomic-scale interlayer.

Description

TECHNICAL FIELD [0001] The present invention relates to a particle including an atom-scale channel, a method for producing the same, and a catalyst containing the same. BACKGROUND ART [0002]

We claim: 1. A particle comprising an atomic-scale channel, wherein at least one of the atomic-scale channels is formed on a surface, or a surface and an interior of the particle; An efficient and selective electrochemical conversion catalyst to a catalyst comprising said particles, in particular to a high value-added C ₂₊ fuel of carbon dioxide; And a process for producing the particles.

The chemical reaction process accelerated by the catalyst is composed of (1) adsorption of the reactant on the catalyst reaction site, (2) reaction, and (3) desorption of the catalyst surface on the catalyst surface. therefore. If the adsorption specificity of the catalyst surface is changed, the activity and selectivity of the chemical reaction can also be greatly changed.

Therefore, in order to improve the catalytic activity such as activity and selectivity, mainly the study of controlling the adsorption specificity of the catalyst mainly by increasing the reaction site of the catalyst is mainly performed, and based on the adsorption / desorption energy of the reactant or the intermediate product , A technique for atomically controlling the surface of the catalyst and the reaction sites inside the catalyst has hardly been studied.

On the other hand, carbon dioxide is one of the representative greenhouse gases that cause global warming. Carbon dioxide is mainly generated when fossil fuels are burned, and billions of tons of carbon dioxide are produced each year. Accordingly, countries around the world are spurring the development of technologies for converting carbon dioxide into high value-added fuels or industrial chemicals using electrochemical and / or photochemical methods to alleviate the emission of carbon dioxide 2014-0012017, etc.).

However, the carbon dioxide conversion technology has many limitations such as its efficiency, selectivity, and conversion rate for commercial use. The carbon dioxide conversion technique is basically a catalytic reaction, and most of the problems (such as expensive noble metal catalysts, low catalytic activity, and abrupt catalyst deterioration) that hinder commercialization are due to the catalyst.

Therefore, in order to commercialize the carbon dioxide conversion technology, development of a catalyst capable of generating a desired high-value-added product with high efficiency and good selection over a long period of time by inputting a small amount of energy is primarily demanded.

We claim: 1. A particle comprising an atomic-scale channel, wherein at least one of the atomic-scale channels is formed on a surface, or a surface and an interior of the particle; An efficient and selective electrochemical conversion catalyst to a catalyst comprising said particles, in particular to a high value-added C ₂₊ fuel of carbon dioxide; And a process for producing the particles.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

A first aspect of the present application is directed to a particle comprising an atomic-scale channel, wherein at least one of the atomic-scale channels is formed on a surface of the particle, to provide.

A second aspect of the present application is a catalyst comprising particles comprising an atomic-scale channel according to the first aspect, wherein at least one of the atomic-scale channels is present on the surface of the particle, Wherein the inner surface of the atomic-scale channel comprised in the particles comprises a reduced metal.

A third aspect of the present invention is a method of forming a metal-compound-containing particle on a first surface, comprising: electrochemically litholytically laminating a metal compound-containing particle to form one or more atomic-scale channels on the particle surface, Wherein the width of the atomic-scale channel is controlled by controlling the degree of lithiation, and the surface of the metal compound, or the surface of the metal compound during the lithiation process, At least a portion of which is reduced to form the atomic-scale channel, and wherein an inner surface of the atomic-scale channel included in the particle comprises the reduced metal.

In embodiments herein, a particle according to the present invention comprises at least one atomic-scale channel on its surface, or across its surface and interior, and the width of the atomic-scale channel can be controlled in angstrom units.

In embodiments herein, a particle according to the present invention includes at least one atomic-scale channel whose surface, or surface and interior width, can be controlled in angstrom units, such that the atomic- / RTI > and / or can form strong and stable bonds with the intermediate product, and therefore are very useful as catalysts.

In embodiments of the present invention, the catalyst has an atomic-scale channel that is very strong and can stably bond with the reactants and / or intermediates of the catalytic reaction, so that the current density and Faraday efficiency are significantly higher, And / or a high degree of selectivity.

In embodiments herein, the catalyst may serve as a catalyst for the electrochemical reduction of oxygen atom-containing materials, and may in particular act as a catalyst for the reduction of carbon dioxide, sulfur oxides, or nitrogen oxides.

In embodiments of the present invention, the catalyst comprises the atomic-scale channel controlled in angstrom units so that the selectivity for a high value-added hydrocarbon product of C ₂₊ or greater, produced by carbon dioxide reduction or electrochemical reduction, Can be significantly increased compared to particles without an atom-scale channel.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagram of the results and models calculated for quantum chemistry in one embodiment of the invention.
FIG. 2 is a diagram showing structural control of CuO _x nanoparticles by electrochemical lithiation in one embodiment of the present invention. FIG. Specifically, FIG. 2A shows an electrochemical lithium charge / discharge process according to a capacity profile, and FIG. 2B is a schematic view of CuO _x particles during the process steps of steps I to V. FIG. 2C is a TEM (transmission electron microscope) photograph of CuO _x particles at the same point during the progressive lithiation process steps from step I to V, and Fig. 2D shows the distribution of d _s values at each step .
Figure 3 is TEM and STEM (scanning transmission electron microscope) images of CuO _x clusters in steps III, IV, and V in one embodiment of the invention.
4 is a graph showing PXRD (powder X-ray diffraction) patterns obtained after each lithiation step, in one embodiment of the present invention.
5 is according to one embodiment of the present application, it is not modified (blank, hereinafter referred to as "blank" also known as) _x CuO particles and a step to process Ⅰ X- ray absorption spectrum of the treated sample of Ⅴ.
Figure 6 is XPS (X-ray photoelectron spectroscopy) spectra of blank CuOx particles and processed samples of steps I to V, in one embodiment of the invention.
Figure 7 is a pupil size distribution simulated by the HK (Horvath-Kawazoe) method for N ₂ adsorption / desorption measurements of blank CuOx particles and lithiated samples from steps I to V, in one embodiment of the invention.
Figure 8 shows the electrochemical carbon dioxide reduction characteristics of lithiated-treated copper oxide nanoparticles in one embodiment of the invention.
Figure 9 shows the Faraday efficiency of a lithiated sample at various applied potentials in one embodiment of the invention.
Figure 10 shows the catalytic properties of periodically and repeatedly lithiated samples in one embodiment of the invention.
Figure 11 shows the catalyst properties of samples after step III according to different mass loading in one embodiment of the invention.
Figure 12 shows the catalytic properties of an oxide-derived Cu catalyst in one embodiment of the invention.
Figure 13 shows the catalyst properties of an O ₂ plasma treated Cu catalyst in one embodiment of the invention.
FIG. 14 is a temperature-programmed desorption (hereinafter also referred to as " TPD ") spectrum of CO gas in one embodiment of the present invention.
Figure 15 shows the amount of CO emitted during the TPD analysis in one embodiment of the invention.
FIG. 16 is a graphical representation of the results of a comparison of -0.9 V vs. And the current density of the sample in step III for CO2RR under an applied voltage of RHE.
Figure 17 illustrates Operando XAS (X-ray absorption spectroscopy) analysis for determining oxidized Cu species in lithiated samples during CO 2 RR in one embodiment of the present invention.
18 is O (oxygen) 1s spectrum obtained in an ex situ XPS analysis under inert gas conditions to determine the oxygen species of the lithiated samples before and after the CO2RR, in one embodiment of the present invention.
Figure 19 is a graph of the effect of CC coupling activity on the specific surface area, electrochemical surface area, GB (grain boundary) surface area, and defect oxygen density and Cu oxidation state, respectively, as a function of d _s Lt; / RTI >

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

Throughout this specification, when a member is " on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as " including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise. The terms " about ", " substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure. The word " step (or step) " or " step " used to the extent that it is used throughout the specification does not mean " step for.

Throughout this specification, the term " combination thereof " included in the expression of the machine form means one or more combinations or combinations selected from the group consisting of the constituents described in the expression of the machine form, And the like.

Throughout this specification, the description of "A and / or B" means "A or B, or A and B".

Throughout this specification, "RHE" refers to a reversible hydrogen electrode and "CO2RR" refers to the electrochemical reduction of carbon dioxide.

Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these embodiments and examples and drawings.

A first aspect of the present application is directed to a particle comprising an atomic-scale channel, wherein at least one of the atomic-scale channels is formed on a surface of the particle, to provide.

In one embodiment of the invention, the width of the atomic-scale channel may be less than about 1 nm. For example, the width of the atomic-scale channel may be less than about 1 nm, less than about 9 A, less than about 8 A, less than about 7 A, less than about 6 A, less than about 5 A, less than about 4 A, Or about 2 A or less, but is not limited thereto. Also, for example, the width of the atomic-scale channel may be less than or equal to about 7 angstroms.

In one embodiment of the invention, the width of the atomic-scale channel may be greater than about 1 A to less than about 1 nm, but is not limited thereto. For example, the width of the atomic-scale channel may be at least about 1 A to about 1 nm, at least about 1 A to about 9 A, at least about 1 A to about 8 A, at least about 1 A to about 7 A From about 1 A to about 5 A, from about 1 A to less than about 4 A, from about 1 A to less than about 3 A, from about 1 A to less than about 2 A At least about 2 angstroms to about 7 angstroms, at least about 2 angstroms to about 6 angstroms, and at least about 2 angstroms, From about 2 A to less than about 5 A, from about 2 A to less than about 4 A, from about 2 A to less than about 3 A, from about 3 A to less than about 1 nm, from about 3 A to less than about 9 A Less than about 3 angstroms to about 8 angstroms, less than about 3 angstroms to about 7 angstroms, less than about 3 angstroms to less than about 6 angstroms, less than about 3 angstroms, At least about 4 angstroms, at least about 4 angstroms, at least about 4 angstroms, at least about 4 angstroms, at least about 4 angstroms, at least about 4 angstroms, At least about 7 angstroms, at least about 4 angstroms and at least about 6 angstroms, at least about 4 angstroms and at least about 5 angstroms, at least about 5 angstroms and at least about 1 nm, at least about 5 angstroms and at least about 9 angstroms, From about 6 A to less than about 1 A, from about 6 A to less than about 9 A, from about 6 A to less than about 6 A, At least about 7 angstroms, at least about 7 angstroms, at least about 7 angstroms, at least about 7 angstroms, at least about 1 nanometers, at least about 7 angstroms, at least about 9 angstroms, at least about 7 angstroms, Less than about 1 nm, from about 8 A to less than about 9 A, or from about 9 A to less than about 1 nm, The. Also, for example, the width of the atomic-scale channel may be at least about 5 A to about 6 A or less.

In one embodiment of the invention, the inner surface of the atomic-scale channel included in the particles may comprise a reduced metal. In one embodiment of the invention, the surface between the channels in the particle may comprise the reduced metal. In one embodiment of the present invention, the inner surface of the atomic-scale channel included in the particle and the remaining surface of the particle may include, but are not limited to, a reduced metal.

In one embodiment of the invention, the atomic-scale channel located on the surface of the particle among the atomic-scale channels is an open surface of the particle, and the atomic-scale channel can have a three- And may have a one- or two-dimensional shape upon observation at the nanoscale, but the present invention is not limited thereto.

In one embodiment of the present invention, the atomic-scale channel or the inner space of the channel is a space formed by an atomic scale size, and the atomic-scale channel or the inner part of the channel The space may be represented as an atom-scale interspacing, an atom-scale interlayer, or an atom-scale interplanar spacing, but is not limited thereto.

In one embodiment, the one or more atomic-scale channels may include regular or irregular shapes and may be separated or connected to each other, but are not limited thereto.

In one embodiment, the atomic-scale channel included in the particle is formed by a process comprising electrochemically lithiating a metal compound-containing particle and then delignifying the atomic-scale channel, May include the reduced metal formed by reduction of the metal compound during the lithiation.

In one embodiment of the present invention, the width of the atomic-scale channel may be controlled by the cutoff voltage of the electrochemical lithiation of the metal compound-containing particles, but is not limited thereto.

In one embodiment of the present invention, the metal compound is selected from the group consisting of Mg, Al, Au, Ag, Cd, Co, Cr, Cu, In, Ir, Mo, Nb, Ni, Os, Pd, Pt, Rh, But are not limited to, compounds containing one or more metal elements selected from Ti, V, W, Zn, Sc, Y, Zr, Hf, Ta, Mn, Fe, Tc and Re . In one embodiment of the present invention, the metal may have a standard reduction potential higher than the standard reduction potential of lithium, but is not limited thereto.

In one embodiment of the present invention, the metal compound is selected from the group consisting of Mg, Al, Au, Ag, Cd, Co, Cr, Cu, In, Ir, Mo, Nb, Ni, Os, Pd, Pt, Rh, And may include oxides of one or more metals selected from Ti, V, W, Zn, Sc, Y, Zr, Hf, Ta, Mn, Fe, Tc and Re.

In one embodiment of the invention, the reduced metal is selected from the group consisting of Mg, Al, Au, Ag, Cd, Co, Cr, Cu, In, Ir, Mo, Nb, Ni, Os, Pd, Pt, , And one or more metals selected from Ti, V, W, Zn, Sc, Y, Zr, Hf, Ta, Mn, Fe, Tc and Re. In one embodiment of the present invention, the metal may have a standard reduction potential higher than the standard reduction potential of lithium, but is not limited thereto.

In one embodiment of the present invention, the average diameter of the particles is not particularly limited. For example, it may be of the order of nanometers to micrometers in size, but is not limited thereto. For example, the average diameter of the particles may be less than about 10 urn, less than about 1 urn, less than about 500 nm, less than about 300 nm, less than about 100 nm, from about 30 nm to about 500 nm, From about 30 nm to about 50 nm, from about 30 nm to about 50 nm, from about 30 nm to about 50 nm, from about 30 nm to about 300 nm, from about 30 nm to about 200 nm, from about 30 nm to about 100 nm, From about 50 nm to about 500 nm, from about 50 nm to about 400 nm, from about 50 nm to about 300 nm, from about 50 nm to about 200 nm, from about 50 nm to about 100 nm, from about 50 nm to about 80 nm, About 60 nm to about 100 nm, about 60 nm to about 500 nm, about 60 nm to about 400 nm, about 60 nm to about 300 nm, about 60 nm to about 200 nm, about 60 nm to about 100 nm, 80 nm to about 500 nm, about 80 nm to about 500 nm, about 80 nm to about 400 nm, about 80 nm to about 300 nm, about 80 nm to about 200 nm, or about 80 nm to about 100 nm, It is not.

In one embodiment of the invention, the volume density of the atomic-scale channel may be in the range of about 0.01 to about 0.2 per unit volume of the particles, but is not limited thereto. For example, the volume density of the atomic-scale channels may be from about 0.01 to about 0.2, from about 0.01 to about 0.15, from about 0.01 to about 0.1, from about 0.01 to about 0.08, from about 0.01 to about 0.06, From about 0.01 to about 0.04, from about 0.01 to about 0.02, from about 0.02 to about 0.2, from about 0.02 to about 0.15, from about 0.02 to about 0.1, from about 0.02 to about 0.08, from about 0.02 to about 0.06, from about 0.02 to about 0.04, From about 0.04 to about 0.1, from about 0.04 to about 0.1, from about 0.04 to about 0.08, from about 0.04 to about 0.06, from about 0.06 to about 0.2, from about 0.06 to about 0.15, from about 0.06 to about 0.1, from about 0.06 to about 0.08 , From about 0.08 to about 0.2, from about 0.08 to about 0.15, or from about 0.08 to about 0.1.

A second aspect of the present application is a catalyst comprising particles comprising an atomic-scale channel according to the first aspect, wherein at least one of the atomic-scale channels is present on the surface of the particle, Wherein the inner surface of the atomic-scale channel comprised in the particles comprises a reduced metal.

Although a detailed description of the parts overlapping with the first aspect of the present application is omitted, the description of the first aspect of the present application may be applied to the second aspect of the present invention.

In one embodiment of the invention, the width of the atomic-scale channel may be less than about 1 nm. For example, the width of the atomic-scale channel may be less than about 1 nm, less than about 9 A, less than about 8 A, less than about 7 A, less than about 6 A, less than about 5 A, less than about 4 A, Or about 2 A or less, but is not limited thereto. Also, for example, the width of the atomic-scale channel may be less than or equal to about 7 angstroms.

In one embodiment of the invention, the width of the atomic-scale channel may be greater than about 1 A to less than about 1 nm, but is not limited thereto. For example, the width of the atomic-scale channel may be at least about 1 A to about 1 nm, at least about 1 A to about 9 A, at least about 1 A to about 8 A, at least about 1 A to about 7 A From about 1 A to about 5 A, from about 1 A to less than about 4 A, from about 1 A to less than about 3 A, from about 1 A to less than about 2 A At least about 2 angstroms to about 7 angstroms, at least about 2 angstroms to about 6 angstroms, and at least about 2 angstroms, From about 2 A to less than about 5 A, from about 2 A to less than about 4 A, from about 2 A to less than about 3 A, from about 3 A to less than about 1 nm, from about 3 A to less than about 9 A Less than about 3 angstroms to about 8 angstroms, less than about 3 angstroms to about 7 angstroms, less than about 3 angstroms to less than about 6 angstroms, less than about 3 angstroms, At least about 4 angstroms, at least about 4 angstroms, at least about 4 angstroms, at least about 4 angstroms, at least about 4 angstroms, at least about 4 angstroms, At least about 7 angstroms, at least about 4 angstroms and at least about 6 angstroms, at least about 4 angstroms and at least about 5 angstroms, at least about 5 angstroms and at least about 1 nm, at least about 5 angstroms and at least about 9 angstroms, From about 6 A to less than about 1 A, from about 6 A to less than about 9 A, from about 6 A to less than about 6 A, At least about 7 angstroms, at least about 7 angstroms, at least about 7 angstroms, at least about 7 angstroms, at least about 1 nanometers, at least about 7 angstroms, at least about 9 angstroms, at least about 7 angstroms, Less than about 1 nm, from about 8 A to less than about 9 A, or from about 9 A to less than about 1 nm, The. Also, for example, the width of the atomic-scale channel may be at least about 5 A to about 6 A or less.

In one embodiment of the invention, the inner surface of the atomic-scale channel included in the particles may comprise a reduced metal. In one embodiment of the invention, the surface between the channels in the particle may comprise the reduced metal. In one embodiment of the present invention, the inner surface of the atomic-scale channel included in the particle and the remaining surface of the particle may include, but are not limited to, a reduced metal.

In one embodiment of the invention, the atomic-scale channel located on the surface of the particle among the atomic-scale channels is an open surface of the particle, and the atomic-scale channel can have a three- And may have a one- or two-dimensional shape upon observation at the nanoscale, but the present invention is not limited thereto.

In one embodiment of the present invention, the atomic-scale channel or the inner space of the channel is a space formed by an atomic scale size, and the atomic-scale channel or the inner part of the channel The space may be represented as an atom-scale interspacing, an atom-scale interlayer, or an atom-scale interplanar spacing, but is not limited thereto.

In one embodiment, the one or more atomic-scale channels may include regular or irregular shapes and may be separated or connected to each other, but are not limited thereto.

In one embodiment, the atomic-scale channel included in the particle is formed by a process comprising electrochemically lithiating a metal compound-containing particle and then delignifying the atomic-scale channel, May be that the metal compound comprises a reduced metal.

In one embodiment of the present invention, the width of the atomic-scale channel may be controlled by the cutoff voltage of electrochemical lithiation of the particles containing the metal compound, but is not limited thereto.

In one embodiment of the present invention, in the catalyst, the particles may serve as a catalyst for reducing an oxygen atom-containing material, but the present invention is not limited thereto. The catalyst may serve as a catalyst for reduction of the oxygen atom-containing material in a gaseous state or a liquid state, but is not limited thereto.

In one embodiment of the invention, the oxygen atom-containing material may include, but is not limited to, carbon dioxide, sulfur oxides (SO _x ), or nitrogen oxides (NO _x ). In addition, the oxygen atom-containing material may include carbon dioxide.

In one embodiment of the present invention, the reduction may be performed by electrochemical reduction, but is not limited thereto.

In one embodiment of the present invention, the activity and / or selectivity of the catalyst may be controlled according to the magnitude of the width of the atomic-scale channel included in the particles.

In one embodiment of the present invention, the width of the atomic-scale channel before and after the reduction using the catalyst may be kept constant, but the present invention is not limited thereto.

In one embodiment of the present invention, the metal compound is selected from the group consisting of Mg, Al, Au, Ag, Cd, Co, Cr, Cu, In, Ir, Mo, Nb, Ni, Os, Pd, Pt, Rh, But are not limited to, compounds containing one or more metal elements selected from Ti, V, W, Zn, Sc, Y, Zr, Hf, Ta, Mn, Fe, Tc and Re . In one embodiment of the present invention, the metal may have a standard reduction potential higher than the standard reduction potential of lithium, but is not limited thereto.

In one embodiment of the present invention, the metal compound is selected from the group consisting of Mg, Al, Au, Ag, Cd, Co, Cr, Cu, In, Ir, Mo, Nb, Ni, Os, Pd, Pt, Rh, And may include oxides of one or more metals selected from Ti, V, W, Zn, Sc, Y, Zr, Hf, Ta, Mn, Fe, Tc and Re.

In one embodiment of the invention, the reduced metal is selected from the group consisting of Mg, Al, Au, Ag, Cd, Co, Cr, Cu, In, Ir, Mo, Nb, Ni, Os, Pd, Pt, , And one or more metals selected from Ti, V, W, Zn, Sc, Y, Zr, Hf, Ta, Mn, Fe, Tc and Re. In one embodiment of the present invention, the metal may be used without limitation if it has a standard reduction potential higher than the standard reduction potential of lithium, as long as it is known to have the desired catalytic activity.

In one embodiment of the present invention, the average diameter of the particles is not particularly limited. For example, it may be of the order of nanometers to micrometers in size, but is not limited thereto. For example, the average diameter of the particles may be less than about 10 urn, less than about 1 urn, less than about 500 nm, less than about 300 nm, less than about 100 nm, from about 30 nm to about 500 nm, From about 30 nm to about 50 nm, from about 30 nm to about 50 nm, from about 30 nm to about 50 nm, from about 30 nm to about 300 nm, from about 30 nm to about 200 nm, from about 30 nm to about 100 nm, From about 50 nm to about 500 nm, from about 50 nm to about 400 nm, from about 50 nm to about 300 nm, from about 50 nm to about 200 nm, from about 50 nm to about 100 nm, from about 50 nm to about 80 nm, About 60 nm to about 100 nm, about 60 nm to about 500 nm, about 60 nm to about 400 nm, about 60 nm to about 300 nm, about 60 nm to about 200 nm, about 60 nm to about 100 nm, 80 nm to about 500 nm, about 80 nm to about 500 nm, about 80 nm to about 400 nm, about 80 nm to about 300 nm, about 80 nm to about 200 nm, or about 80 nm to about 100 nm, It is not.

In one embodiment of the invention, the volume density of the atomic-scale channel may be in the range of about 0.01 to about 0.2 per unit volume of the particles, but is not limited thereto. For example, the volume density of the atomic-scale channels may be from about 0.01 to about 0.2, from about 0.01 to about 0.15, from about 0.01 to about 0.1, from about 0.01 to about 0.08, from about 0.01 to about 0.06, From about 0.01 to about 0.04, from about 0.01 to about 0.02, from about 0.02 to about 0.2, from about 0.02 to about 0.15, from about 0.02 to about 0.1, from about 0.02 to about 0.08, from about 0.02 to about 0.06, from about 0.02 to about 0.04, From about 0.04 to about 0.1, from about 0.04 to about 0.1, from about 0.04 to about 0.08, from about 0.04 to about 0.06, from about 0.06 to about 0.2, from about 0.06 to about 0.15, from about 0.06 to about 0.1, from about 0.06 to about 0.08 , From about 0.08 to about 0.2, from about 0.08 to about 0.15, or from about 0.08 to about 0.1.

In one embodiment of the present application, the width of the atomic-scale channel of the particles is less than or equal to about 7 ANGSTROM, and the particles are used as catalysts to produce carbon dioxide, particularly hydrocarbons of C ₂₊ or greater, The selectivity for the product may be increased relative to the particles without the atomic-scale channel. For example, the selectivity for the C ₂₊ or higher hydrocarbon product may be at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, or at least about 90% Also, the selectivity for the C ₂₊ or higher hydrocarbon product may vary depending on the number, shape, width, length, or depth of the atom-scale channels formed in the particles contained in the actual catalyst. For example, it may be, but is not limited to, a carbon-carbon coupling efficiency that varies with the number, shape, width, length, or depth of the atom-scale channels formed in the particle.

In one embodiment of the invention, the particle has a width of the atomic-scale channel of not less than about 5 A and not more than about 6 A, and the particle is used as a catalyst to produce carbon dioxide, _The selectivity for ₂₊ or more hydrocarbon products may be increased relative to the particles without the atomic-scale channel. For example, the selectivity for the C ₂₊ or higher hydrocarbon product may be at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, or at least about 90% Also, the selectivity for the C ₂₊ or higher hydrocarbon product may vary depending on the number, shape, width, length, or depth of the atom-scale channels formed in the particles included in the actual catalyst production. For example, it may be, but is not limited to, a carbon-carbon coupling efficiency that varies with the number, shape, width, length, or depth of the atom-scale channels formed in the particle.

In one embodiment of the invention, the particle according to the invention comprises at least one atomic-scale channel on its surface, or on its surface and inside, which can be controlled in units of angstroms (A) Can form strong and stable bonds with the reactants and / or intermediates of the catalysts, and thus are very useful as catalysts.

In one embodiment of the invention, the catalyst has an atomic scale channel or gap that is very strong and stably bound to the reactants and / or intermediates of the catalytic reaction, so that the current density and the faraday efficiency are significantly high, And / or selectivity.

In one embodiment of the present invention, the catalyst can act as a catalyst for electrochemical reduction of oxygen atom-containing materials in particular, and can act as a catalyst for the reduction of carbon dioxide, sulfur oxide, or nitrogen oxides.

In one embodiment of the invention, the catalyst comprises the atomic-scale channel controlled in angstrom units, so that the selectivity for a C ₂₊ or higher hydrocarbon product produced by carbon dioxide reduction is less than the atomic-scale channel Can be significantly increased compared to the particles.

In one embodiment of the present invention, the electrochemical reduction method of carbon dioxide using the catalyst is a method of generating C _{2 +} organic matter by electrochemically reducing carbon dioxide using an electrode including the carbon dioxide reduction catalyst . Here, the organic material of the C ₂₊ is C2 to C4 may be organic materials, for example, the C2 to C4 organic substances. However can include ethylene, propylene, butylene, ethanol, propanol, butanol, or acetate, But is not limited thereto. Specifically, the C2 or higher organic matter may include ethylene and / or ethanol.

In the electrochemical reduction method according to an embodiment of the present invention, the loading amount of the catalyst on the electrode is about 1 μg / cm ² Cm ² to about 50 μg / cm ² , preferably from about 5 μg / cm ² to about 20 μg / cm ² , more preferably from about 11 μg / cm ² to about 20 μg / cm ² . The catalyst may be loaded by drop-casting a catalyst-containing solution onto an electrode or a glassy carbon substrate, but is not limited thereto.

In the electrochemical reduction method according to an embodiment of the present invention, the voltage applied to the electrode during electrochemical reduction is about -0.7 V to about -1.5 V, preferably about -0.7 V to about -1 V ( V vs RHE). ≪ / RTI > For example, the voltage applied to the electrode may be from about -0.7 V to about -1.5 V, from about -0.7 V to about -1.2 V, from about -0.7 V to about -1 V, from about -0.7 V From about -0.9 V to about -1.5 V, from about -0.9 V to about -1.2V, from about -0.9V to about -1V, from -1V to about -1.5V, or from about -1V to about -1.5V -1.2 V, but is not limited thereto.

The electrochemical reduction method of carbon dioxide according to one embodiment of the present invention may be performed using any cell structure, electrolyte, and counter electrode known to be used for electrochemically reducing carbon dioxide to produce a product of C ₂₊ . For example, the electrochemical reduction of carbon dioxide may be performed by using a separation membrane that separates a cathode region and an anode region; A cathode which is an electrode including the aforementioned carbon dioxide reducing catalyst disposed in the cathode region; And a cathode electrolyte positioned in the cathode region and in contact with the cathode and saturated with carbon dioxide; An anode disposed in the anode region; And an anode electrolyte in contact with the anode. At this time, fresh electrolyte may be injected into each of the cathode region and the anode region through the injection port, and the electrolyte and the reaction product after the reaction may be discharged through the discharge port. The separation membrane may be an ion exchange membrane, and the ion exchange membrane may be a cation exchange membrane or an anion exchange membrane. The anode, the cathode electrolyte, and the anode electrolyte can be used without limitation as long as they are an anode material, a cathode electrolyte material, and an anode electrolyte material known to be used for electrochemically reducing carbon dioxide. For example, the anode may include, but is not limited to, noble metals such as platinum, rhodium, gold, and / or noble metal oxides. For example, the cathode electrolyte and the anode electrolyte may be the same or different from each other, and the cathode electrolyte and the anode electrolyte may be electrolytic solutions. For example, the electrolytic solution may be an aqueous or non-aqueous electrolytic solution. Examples of the cathode electrolytic solution may include a non-aqueous or aqueous electrolytic solution including alkali metal bicarbonate, carbonate, sulfate, phosphate, borate, ammonium and hydroxide, chloride, bromite and other organic / , But is not limited thereto. Examples of the anode electrolytic solution include, but are not limited to, a non-aqueous or aqueous electrolytic solution containing an alkali metal hydroxide, ammonium hydroxide, inorganic acid, organic acid, or alkali halide. The solvent of the non-aqueous liquid electrolyte may be an organic solvent known to be used in the electrochemical reduction of carbon dioxide. Typical examples thereof include nitrile solvents such as acetonitrile, alcohol solvents such as methanol and the like, Ionic liquids such as ether-based solvents, imidazolium-based solvents, and the like, but are not limited thereto.

The third aspect of the present application is directed to a method of forming a metal-compound-containing particle, comprising electrochemically lithiating and then depolitilizing metal compound-containing particles to form at least one atomic-scale channel on the surface, Scale channel is controlled by controlling the degree of lithiation, and during the lithiation process, the surface of the metal compound, or the surface and the inner surface of the metal compound during the lithiation process, At least a portion of which is reduced to form the atomic-scale channel and the inner surface of the atomic-scale channel included in the particle comprises the reduced metal.

Although the detailed description of the parts overlapping with the first aspect of the present invention is omitted, the description of the first aspect of the present invention can be applied equally to the third aspect of the present invention.

In one embodiment of the invention, the inner surface of the atomic-scale channel included in the particles may comprise a reduced metal. In one embodiment of the invention, the surface between the channels in the particle may comprise the reduced metal. In one embodiment of the present invention, the inner surface of the atomic-scale channel included in the particle and the remaining surface of the particle may include, but are not limited to, a reduced metal.

In one embodiment of the invention, the atomic-scale channel located on the surface of the particle among the atomic-scale channels is an open surface of the particle, and the atomic-scale channel can have a three- And may have a one- or two-dimensional shape upon observation at the nanoscale, but the present invention is not limited thereto.

In one embodiment of the present invention, the atomic-scale channel or the inner space of the channel is a space formed by an atomic scale size, and the atomic-scale channel or the inner part of the channel The space may be represented as an atom-scale interspacing, an atom-scale interlayer, or an atom-scale interplanar spacing, but is not limited thereto.

In one embodiment, the one or more atomic-scale channels may include regular or irregular shapes and may be separated or connected to each other, but are not limited thereto.

In one embodiment, the atomic-scale channel included in the particle is formed by a process comprising electrochemically lithiating a metal compound-containing particle and then delignifying the atomic-scale channel, May include the reduced metal formed by reduction of the metal compound during the lithiation.

In one embodiment, the lithiation may include applying a constant current using an electrochemical cell and a cut-off voltage of greater than 0 V to about 3 V, and the cut- The voltage is a voltage based on Li / Li ⁺ , but is not limited thereto. For example, the cut-off voltage may be greater than 0 V to less than about 3 V, greater than 0 V to less than about 3 V, greater than 0 V to less than about 2.5 V, greater than 0 V to less than about 2 V, greater than 0 V, From greater than 0 V to about 1.4 V, from greater than 0 V to about 1.2 V, from greater than 0 V to about 1 V, from greater than 0 V to about 0.8 V, from greater than 0 V to about 0.6 V, Between about 0.2 V and about 3 V, between about 0.2 V and about 2.5 V, between about 0.2 V and about 0.4 V, between about 0.2 V and about 0.2 V, between about 0.2 V and about 3 V, About 0.2 V or more and about 1.5 V or less, about 0.2 V or more and about 1.4 V or less, about 0.2 V or more and about 1.2 V or less, about 0.2 V or more and about 1 V or less, about 0.2 About 0.4 V or more to about 3 V or less, about 0.4 V or more to about 3 V or less, about 0. 0 V or more to about 0.6 V or less, about 0.2 V or more to about 0.4 V or less, About 0.4 V or more to about 2 V or less, about 0.4 V or more to about 1.5 V or less, about 0.4 V or more to about 1.4 V or less, about 0.4 V or more to about 1.2 V or less, about 4 V or more to about 2.5 V or less From about 0.4 V to about 0.8 V, from about 0.4 V to less than about 0.8 V, from about 0.4 V to less than about 0.6 V, from about 0.6 V to less than about 3 V, from about 0.6 V to less than about 3 V, About 0.6 V or more to about 1.5 V or less, about 0.6 V or more to about 1.4 V or less, about 0.6 V or more to about 1.2 V or less, about 0.6 V or more to about 2.5 V or less, about 0.6 V or more to about 2 V or less, From about 0.6 V to about 1 V, from about 0.6 V to about 0.8 V, from about 0.8 V to about 3 V, from about 0.8 V to less than about 3 V, from about 0.8 V to about 2.5 V, From about 0.8 V or more to about 2 V or less, from about 0.8 V or more to about 1.5 V or less, from about 0.8 V or more to about 1.4 V or less, from about 0.8 V or more to about 1.2 V or less, About 1 V or more to about 3 V or less, about 1 V or more to about 3 V or less, about 1 V or more to about 2.5 V or less, about 1 V or more to about 2 V or less, or about 1 V or more From about 1 V to about 1.2 V, from about 1.2 V to about 3 V, from about 1.2 V to less than about 3 V, from about 1.2 V to about 1.5 V, About 1.2 V or more to about 2 V or less, about 1.2 V or more to about 1.5 V or less, about 1.2 V or more to about 1.4 V or less, about 1.4 V or more to about 3 V or less, or about 1.4 V or more About 1.4 V or more to about 2.5 V or less, about 1.4 V or more to about 2 V or less, or about 1.4 V or more to about 1.5 V or less. For example, the cut-off voltage may be greater than 0 V to less than about 1.5 V, greater than 0 V to less than about 1 V, greater than 0 V to less than about 0.5 V, greater than about 0.5 V to less than about 1.5 V, About 1 V or less, about 1 V or more and about 1.5 V or less, about 1 V or more and about 1.4 V or less. Also, for example, the cut-off voltage may be greater than about 1 V to about 1.4 V or less.

 In one embodiment of the present invention, the width of the atomic-scale channel may be controlled by the cutoff voltage of the electrochemical lithiation of the metal compound-containing particles. This means that the average width of the channel of the atomic scale can be adjusted by the cut-off voltage at the time of the constant current discharge (lithium ionization), that is, the voltage at which the lithium ionization is stopped.

In one embodiment of the present invention, the process of electrochemically litholating the metal compound-containing particles comprises the steps of: a) forming a first electrode on which a layer of a material containing the metal compound is formed on a collector, a second electrode of metal lithium, Preparing an electrochemical cell including a separator and an electrolyte positioned between the electrode and the second electrode; And b) applying a cut-off voltage of greater than 0 V to less than about 3 V, or greater than 0 V to less than about 3 V, using a manufactured electrochemical cell to effect lithiation .

In one embodiment of the present invention, the electrochemical cell in step a) may correspond to a conventional lithium half cell using a metal compound-containing particle as an active material, and the lithiation in step b) Lt; RTI ID = 0.0 > a < / RTI > Accordingly, it is needless to say that the cut-off voltage may be a voltage based on Li / Li ⁺ . Therefore, since the electrochemical cell of step a) may correspond to the lithium half cell, the first electrode may be formed by using the metal compound-containing particles on the current collector as an active material and using a conventional lithium secondary battery electrode manufacturing method .

In one embodiment of the present invention, the first electrode can be prepared by applying a slurry containing metal compound-containing particles and an organic binder onto a current collector and then drying the slurry. The organic binder can be used as long as it is a material commonly used for an electrode of a lithium secondary battery, and a polymer that does not chemically react with an electrolytic solution suffices. For example, the organic binder may be selected from the group consisting of polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer, polyvinylidene fluoride-trichlorethylene copolymer, polymethyl methacrylate, polyacrylonitrile, Polyvinylpyrrolidone, polyvinyl acetate, polyethylene-vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinyl alcohol, cyanoethylcellulose Butadiene copolymer, acrylonitrile-styrene-butadiene copolymer, polyimide, polytetrafluoroethylene, and combinations thereof, which is selected from the group consisting of acrylic acid, acrylic acid, methacrylic acid, However, But is not limited to. The current collector may be a conductive material such as graphite, graphene, titanium, copper, platinum, aluminum, nickel, silver or gold.

In one embodiment of the present invention, the second electrode may be a film or a foil of metal lithium, but is not limited thereto. The separator may be a microporous membrane used in a conventional lithium secondary battery.

In one embodiment of the present invention, the electrolyte may be used in a conventional lithium secondary battery without limitations as long as it is a conventional non-aqueous electrolyte that smoothly conducts lithium ions. For example, the non-aqueous electrolyte may include a non-aqueous solvent and a lithium salt, and the lithium salt contained in the electrolyte may include lithium cations and NO ₃ ^-, N (CN) ₂ ^- , BF ₄ ^- , ClO ₄ ^{- _{PF 6 -, (CF 3)}} 2 PF 4 -, (CF 3) 3 PF 3 -, (CF 3) 4 PF 2 -, (CF 3) 5 PF -, (CF 3) 6 P -, CF 3 CO _But are not limited to, salts which provide an anion selected from one or more of the following groups: ^- , CH ₃ CO ₂ ^- , SCN ^- , (CF ₃ CF ₂ SO ₂ ) ₂ N ^- and the like.

In one embodiment of the present invention, the solvent of the electrolyte can be generally used without limitation as long as it is a solvent used as a nonaqueous electrolytic solution in a lithium secondary battery. For example, the solvent is selected from the group consisting of ethylene carbonate, propylene carbonate, 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3-pentylene carbonate, And the like; carbonate-based solvents such as benzene, toluene, xylene, xylene, carbon tetrabromide, Ether solvents such as methyl acetate, ethyl acetate, propyl acetate and the like,? -Butyrolactone, 2-methyl-? -Butyrolactone, 3-methyl- -Methyl-gamma -butyrolactone, and combinations thereof. ≪ / RTI >

In one embodiment of the present invention, the step b) may be a step of lithium-metal compound-containing particles using the electrochemical cell. Specifically, the lithiation of step b) may be performed by using the prepared electrochemical cell to perform lithiation at a constant current and a cut-off voltage condition of more than 0 V to less than about 3 V, or more than 0 V to less than about 3 V Step.

In one embodiment of the present invention, in the lithium ionization process of the constant current condition, uniform lithium ionization is performed in the entire region of the metal compound-containing particle surface, and the metal reduced by rapid and partial lithiation is desorbed from the surface of the nanoparticles , And it is advantageous that a low-current lithization is carried out so that the gaps of the atomic scale can have a narrow size distribution. As a specific example, it is preferable that the current during low-current lithization is about 1 mA / g to about 20 mA / g (the amount of current per 1 g of metal oxide nanoparticles).

In one embodiment of the present invention, after the lithiation of step b) is performed, it is also possible to further perform the step of recovering the lithiated nanoparticles from the first electrode, And a solid-liquid separation. However, the present invention is not limited thereto.

In one embodiment of the present invention, the de-lithiation step may be carried out by acidic washing with acid, and acid of acidic acid may be used without limitation as long as it is a conventional acid used for selectively removing lithium oxide and / or lithium, It is not. For example, the acid may be formic acid or acetic acid, but it is not limited by the type of acid used for acid washing.

In one embodiment of the invention, the width of the atomic-scale channel may be controlled to be less than about 1 nm. For example, the width of the atomic-scale channel may be less than about 1 nm, less than about 9 A, less than about 8 A, less than about 7 A, less than about 6 A, less than about 5 A, less than about 4 A, Or about 2 A or less, but is not limited thereto. Also, for example, the width of the atomic-scale channel can be adjusted to about 7 A or less.

In one embodiment of the invention, the width of the atomic-scale channel may be controlled to be greater than about 1 A to less than about 1 nm, but is not limited thereto. For example, the width of the atomic-scale channel may be at least about 1 A to about 1 nm, at least about 1 A to about 9 A, at least about 1 A to about 8 A, at least about 1 A to about 7 A From about 1 A to about 5 A, from about 1 A to less than about 4 A, from about 1 A to less than about 3 A, from about 1 A to less than about 2 A At least about 2 angstroms to about 7 angstroms, at least about 2 angstroms to about 6 angstroms, and at least about 2 angstroms, From about 2 A to less than about 5 A, from about 2 A to less than about 4 A, from about 2 A to less than about 3 A, from about 3 A to less than about 1 nm, from about 3 A to less than about 9 A Less than about 3 angstroms to about 8 angstroms, less than about 3 angstroms to about 7 angstroms, less than about 3 angstroms to less than about 6 angstroms, less than about 3 angstroms, At least about 4 angstroms, at least about 4 angstroms, at least about 4 angstroms, at least about 4 angstroms, at least about 4 angstroms, at least about 4 angstroms, At least about 7 angstroms, at least about 4 angstroms and at least about 6 angstroms, at least about 4 angstroms and at least about 5 angstroms, at least about 5 angstroms and at least about 1 nm, at least about 5 angstroms and at least about 9 angstroms, From about 6 A to less than about 1 A, from about 6 A to less than about 9 A, from about 6 A to less than about 6 A, At least about 7 angstroms, at least about 7 angstroms, at least about 7 angstroms, at least about 7 angstroms, at least about 1 nanometers, at least about 7 angstroms, at least about 9 angstroms, at least about 7 angstroms, Less than about 1 nm, from about 8 A to less than about 9 A, or from about 9 A to less than about 1 nm, . Also, for example, the width of the atomic-scale channel may be adjusted from about 5 Å to 6 Å.

In one embodiment of the present invention, the metal compound is selected from the group consisting of Mg, Al, Au, Ag, Cd, Co, Cr, Cu, In, Ir, Mo, Nb, Ni, Os, Pd, Pt, Rh, But are not limited to, compounds containing one or more metal elements selected from Ti, V, W, Zn, Sc, Y, Zr, Hf, Ta, Mn, Fe, Tc and Re . In one embodiment of the present invention, the metal may have a standard reduction potential higher than the standard reduction potential of lithium, but is not limited thereto.

In one embodiment of the present invention, the metal compound is selected from the group consisting of Mg, Al, Au, Ag, Cd, Co, Cr, Cu, In, Ir, Mo, Nb, Ni, Os, Pd, Pt, Rh, And may include oxides of one or more metals selected from Ti, V, W, Zn, Sc, Y, Zr, Hf, Ta, Mn, Fe, Tc and Re.

In one embodiment of the invention, the reduced metal is selected from the group consisting of Mg, Al, Au, Ag, Cd, Co, Cr, Cu, In, Ir, Mo, Nb, Ni, Os, Pd, Pt, , And one or more metals selected from Ti, V, W, Zn, Sc, Y, Zr, Hf, Ta, Mn, Fe, Tc and Re. In one embodiment of the invention, the metal may be, but is not limited to, be used as long as it has a standard reduction potential higher than the standard reduction potential of lithium.

In one embodiment of the present invention, the average diameter of the particles is not particularly limited. For example, it may be of the order of nanometers to micrometers in size, but is not limited thereto. For example, the average diameter of the particles may be less than about 10 urn, less than about 1 urn, less than about 500 nm, less than about 300 nm, less than about 100 nm, from about 30 nm to about 500 nm, From about 30 nm to about 50 nm, from about 30 nm to about 50 nm, from about 30 nm to about 50 nm, from about 30 nm to about 300 nm, from about 30 nm to about 200 nm, from about 30 nm to about 100 nm, From about 50 nm to about 500 nm, from about 50 nm to about 400 nm, from about 50 nm to about 300 nm, from about 50 nm to about 200 nm, from about 50 nm to about 100 nm, from about 50 nm to about 80 nm, About 60 nm to about 100 nm, about 60 nm to about 500 nm, about 60 nm to about 400 nm, about 60 nm to about 300 nm, about 60 nm to about 200 nm, about 60 nm to about 100 nm, 80 nm to about 500 nm, about 80 nm to about 500 nm, about 80 nm to about 400 nm, about 80 nm to about 300 nm, about 80 nm to about 200 nm, or about 80 nm to about 100 nm, It is not.

In one embodiment of the invention, the volume density of the atomic-scale channel may be in the range of about 0.01 to about 0.2 per unit volume of the particles, but is not limited thereto. For example, the volume density of the atomic-scale channels may be from about 0.01 to about 0.2, from about 0.01 to about 0.15, from about 0.01 to about 0.1, from about 0.01 to about 0.08, from about 0.01 to about 0.06, From about 0.01 to about 0.04, from about 0.01 to about 0.02, from about 0.02 to about 0.2, from about 0.02 to about 0.15, from about 0.02 to about 0.1, from about 0.02 to about 0.08, from about 0.02 to about 0.06, from about 0.02 to about 0.04, From about 0.04 to about 0.1, from about 0.04 to about 0.1, from about 0.04 to about 0.08, from about 0.04 to about 0.06, from about 0.06 to about 0.2, from about 0.06 to about 0.15, from about 0.06 to about 0.1, from about 0.06 to about 0.08 , From about 0.08 to about 0.2, from about 0.08 to about 0.15, or from about 0.08 to about 0.1.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are given for the purpose of helping understanding of the present invention, but the present invention is not limited to the following Examples.

[ Example ]

1. Experimental Method

(1) Density Functional Theory, DFT ") Calculation

All DFT calculations using a slab model are performed using a dispersion-corrected PBE-D2 function (as described in the Vienna Ab-initio simulation package, VASP) ) And a projector augmented wave pseudopotentials of a 400 eV cut-off reference set. In order to accelerate energy convergence using self-consistent field (SCF) iterations, a Gaussian-smearing technique (smearing temperature k _B T = 0.1 eV for slabs, 0.01 eV for molecules) All calculated energy values were extrapolated to k _B T = 0. The mutual spacing of the slabs was sampled by the Monkhorst-Pack k -point 3 × 3 × 1, but only the gamma points were sampled for molecular calculations. The models were fabricated from a face-centered cubic copper bulk structure with a lattice parameter of 3.615 A. To avoid interactions between periodic replicas in the z-direction, a vacuum spacing of at least 15 A between adjacent images was used in the slab calculation, and a 20 Å × 20 Å × 20 Å box was used for molecular calculations. Spin-polarized wave functions were used for all surface calculations, while spin-restricted wave functions were used for H ₂ , H ₂ O, and CO ₂ . During geometric optimization, the copper atoms of the upper and lower layers of the upper surface were fixed. The distance d between the two surfaces in the initial structure is set to the target value, but may vary slightly to a value less than 0.2 A after optimization depending on the identity of the adsorbate. In this embodiment, energy is based on electron energy. For example, the binding energy (Binding Energy, hereinafter also referred to as "BE") of ^* COOH is ^{BE (* COOH) = E (} * COOH) - E (*) - E (CO 2) - 0.5 × E (H ₂ ), the larger the negative value of BE, the stronger the attraction force.

(2) Preparation of copper particles with controlled width of atomic-scale channels

CuO _x (EPRUI Nanoparticles & Microspheres Co. Ltd.) was cleaned by annealing at 150 ° C under argon for 3 hours before the experiment. CuO _x nanoparticles were mixed with 5 wt% polyvinylidene fluoride (PVDF) dispersed in N-methyl-2-pyrrolidinone (NMP). The black slurry thus obtained was uniformly coated on a Cu foil and dried overnight in a vacuum oven at 80 ° C. 1 M LiPF ₆ dissolved in a mixture of ethyl carbonate (EC) and diethyl carbonate (DEC) (1/1 v / v) as a coin-type cell having Li foil as a counter electrode and an electrolyte Was used for electrochemical lithiation. Test cells containing the nanomaterials were assembled in an Ar-filled glove box using a separator (Celgard) and an electrolyte solution. In the lithiation process, the VSP potential was monitored using a potentiostat (Bio-logic) to maintain a constant current of 10 mA · g ^-1 . After the lithiation process was performed, the resulting samples of each process step were washed with acetone, water, and 1 mM acetic acid solution to remove residual electrolyte, Li ₂ O, and solid electrolyte interlayers.

(3) Operando  analysis

The electrochemical cell was fabricated using three electrodes, an electrolyte, CO ₂ gas bubbling, and a polyimide window. The samples were cast on a PTFE coated carbon paper with a 5 wt% Nafion binder and subjected to 2 cycles of linear sweep voltammetry followed by -0.9 V vs. CO ₂ bubbling under CO ₂ bubbling. RHE was applied. During the electrochemical reduction of carbon dioxide, XANES (X-ray absorption near edge structure) and EXAFS (extended X-ray absorption fine structure) structure) Operando XAS analysis including the measurement was carried out at 10C beam line, wherein the Si (111) was used to determine the double monochromator synchrotron radiation group transmission (transmission) mode, the Athena software using this library IFEFFIT Cu K- edge spectrum obtained by Lt; / RTI >

(4) CO ₂ Of electrochemical reduction of

The lithiated Cu ₂ O nanoparticles were spin-coated onto a glassy carbon substrate, which was used as a cathode for electrochemical reduction of CO ₂ in 0.1 M CsHCO ₃ solution. The electrolyte was first fed with CO ₂ to achieve a pH of 6.8. Electrochemical measurements were performed using a Biologic SP-300 disposable toilet. Peripheral-pressure CO ₂ electrolysis was performed in a custom airtight electrochemical cell made of polycarbonate fitted with a Viton O-ring. The configuration of the electrochemical cell ensures that the working electrode is in parallel with the counter electrode (platinum foil) and has a uniform potential distribution over the entire surface. The geometric surface area of the two electrodes was 1 cm < ^{2 &} gt ;. The average mass loading of the sample at the working electrode was 80 μL (equivalent to ~ 10 μg · cm ^-2 ), which was measured using an XP2U microbalance (d = 0.1 μg, Mettler Toledo). To optimize the catalytic activity, the mass loading of the catalyst solution was adjusted to 50 [mu] L to 150 [mu] L. The anodic compartment and the cathodic compartment were separated using a Selemion AMV anion exchange membrane (thickness 110 μm). Each compartment of the cell contained a small volume of electrolyte and increased the detection limit by concentrating the liquid product. The headspace of the cassette compartment was approximately 3 mL. Before performing the electrolysis of CO _2, the electrolyte in the cathodic compartment was purged for at least 15 minutes by CO _2. During electrolysis, CO ₂ was bubbled through the electrolyte at a flow rate of 5 sccm to prevent CO ₂ depletion. The flow rate of the carbon dioxide was controlled by a mass flow controller (Alicat Scientific) and the gas was first humidified by passing through a water filled bubbler to minimize evaporation of the electrolyte. In all experiments, a platinum foil was used as the counter electrode and an Ag / AgCl electrode (series without leakage) from Innovative Instruments, Inc. was used as the reference electrode. Data was converted to RHE reference scale using the following equation:

E etc. RHE = E vs. Ag / AgCl + 0.197 V + 0.0591 x pH

To ensure the accuracy of the reference electrode, calibration was performed using a hand-held reversible hydrogen electrode. Prior to electrolysis, the solution resistance was first determined by scanning from 1 MHz to 10 Hz using an electrochemical impedance spectrometer. For all the CVs and electrolysis reported in this example, the measurements were generated by setting the potty pot to compensate for 85% of the measured IR drop.

2. Experimental results

We demonstrate that atomic level control of interspacing interspaces can be used to influence the activity and selectivity of Cu nanoparticles for electrochemical CO2RR based on density function theory (DFT) calculations and experimental results. Respectively. It has been found that the DFT calculations of the bond energies of the intermediates related to CO2RR on Cu (100) and Cu (111) surfaces are dependent on the atomic-scale spacing (d _s ) between such surfaces. when d _s = 5 Å to about 6 Å, ^- COOH, ^- CO, ^- binding energy of CHO, and ^* the adsorbed intermediate, such as a CHOH is, and reaches a maximum, ^- CHO + ^* CO → ^- CHOCO and ^- CHO + ^* the formation of the CC bond is highly preferred over the CHO → ^* CHOCHO reaction. ^{Since *} CHOCO and ^* CHOCHO are precursors of ethylene and ethanol, these calculations suggest that the rate of formation of such products is maximized at d _s = 5 A to 6 A. Synchronized by this discovery, atomic-scale spaces between the copper particles are electrochemically lithiated into CuO _x nanoparticles, followed by removal of the deposited lithium oxide and electrochemical reduction of CuO _x to Cu Lt; / RTI > Analysis of the TEM image confirmed that lithiation produced intentional interparticle spacings and operando XANES and EXAFS spectra demonstrated that all oxidized Cu states during the CO2RR were reduced to the metallic phase. Particles with intergranular spacing of between 5 Å and 6 Å exhibit a significantly higher current density for C ₂₊ products and a Faradaic efficiency (FE) of almost 80%, indicating that for unmodified CuO _x - derived Cu It is higher than reported. Theoretical and experimental investigations support the conclusion that the atomic-level control of the width of the channel formed over the surface and interiors advantageously affects the activity and selectivity of Cu nanoparticles for electrochemical CO2RR.

(One) DFT  Calculation

DFT calculations of binding energies for various chemical species assumed to be involved in both the CO2RR and hydrogen evolution reaction (HER) are based on atomic-scale spacing between Cu surfaces for electrochemical reduction of CO ₂ ). Copper nanoparticles with different atomic-scale spaces were simulated using a model formed of two three-layer Cu (100) and Cu (111) (3 × 3) slabs, The surfaces are separated by a distance d _s (Fig. 1a, example of Cu nanoparticles with atomic-level spacing and model of atom-level gap Cu surface used in DFT calculations). This calculation was performed assuming a vacuum on the Cu surface and the influence of the electrode potential was considered using the hydrogen potential electrode method.

The binding energy (BE) of the adsorbed species ^* COOH, ^* CO, ^* CHO, ^* CHOH, and ^* H, which are thought to be involved in CO2RR and HER, was determined as a function of d _s . As shown in FIG. 1B, the BE of ^* COOH, ^* CO, ^* CHO, and ^* CHOH strongly depend on d _s , while in the case of ^* H, vice versa. Figure 1b is a function of surface distance (d _s), the range of the optimal interval and the optimal distance (grayscale region, d- range) will showing the tendency of the binding energy for the intermediates involved in the HER CO2RR and, from this It can be confirmed that the intermediate binds more strongly than the Cu (100) and Cu (111) open surfaces. For comparison, the bond strengths for the same intermediates on the Cu (100) and Cu (111) surfaces are listed. For example, the change in BE for ^* COOH is 0.52 eV and 0.44 eV for Cu (100) and Cu (111), respectively, but only 0.01 eV for ^* H. Importantly, ^- COOH, CO ^{-, -} CHO, and BE ^* strongest for CHOH is between 5.2 Å to 5.8 Å d _s Value. Cu (100) and the change in the BE for the Cu (111) is ^* COOH -0.52 eV to -0.44 eV, ^* CO -0.09 eV to -0.07 eV for about, CHO ^* -0.24 -0.21 eV eV to about , And -0.18 eV to -0.17 eV for ^* CHOH, while for ^* H it is almost zero. These results show that ^* COOH, ^* CHO, and ^* CHOH are the optimum d _s from the Cu (100) and Cu (111) Values into the space between nanoparticles, which suggests that this leads to an increase in the local concentration of the C ₁ intermediates. U = -0.9 V vs. Calculation of the RHE the free energy of the surface (free energy surface) of the applied _{^{bias, * + CO 2 (g)}} + 3 (H + + e -) → * COOH + 2 (H + + e -) → * CO + The reaction sequence of H ₂ O ( l ) + (H ⁺ + e ^- ) → ^* CHO shows that the space between Cu surfaces is d _s = (Figure 1c, free energy diagram for the first three stages of CO2RR) at d _s = 5.2 Å rather than 9 Å.

We have also investigated whether the value of d _s affects the energy of CC bond formation. ^{Since *} CO and ^* CHO are intermediate intermediates in the early stage of CO2RR, their concentrations are expected to be higher than others and we have evaluated the changes in the reaction energy for CC coupling of ^* CHO + ^* CO → ^* CHOCO . The present inventors have found that the two reaction energies strongly depend on d _s and the minimum values for the Cu (100) and Cu (111) open surfaces are d _s = 5.0 A and 6.0 A (Fig. 1D). It is important to note that the minimum reaction energy is more advantageous than the values of Cu (100) and -0.48 eV Cu (111) at -0.95 eV, which means that Cu nanoparticles with optimal values of d _s are ^* CHO + ^* CO → ^* Promotes the CC coupling reaction of CHOCO. The inventors then found that -0.9 V vs. Under the applied bias of the ^{RHE * CHO + * CO + (} H + + e -) → * CHOCO + (H + + e -) → ^* the surface free energy of the reaction sequence of CHOCHO (surface free energy) was calculated. Our calculations show that the first step (CC coupling) at d _s = 5.2 A is -0.43 eV for Cu (100) and -0.19 eV downhill for Cu (111), while d _s = 9 (+0.50 eV for Cu (100) and +0.33 eV for Cu (111)) with respect to Cu (111) at +0.42 eV for Cu (Fig. 1E). Since this step does not involve electron transfer, its energy is not affected by the applied bias. This finding suggests that Cu facets with optimal values of d _s = 5 Å to 6 Å should promote CC bond formation, which is not energetically favored on Cu (100) and Cu (111) open surfaces will be.

To understand whether the atomic-scale spacing between the Cu (100) and Cu (111) surfaces helps stabilize the adsorbed species, the Bader Analysis was performed. The present inventors have confirmed that the enhancement of the adsorption strength of the adsorbed species is due to charge transfer from the second layer to the adsorbate. For example, in the case of ^* CO, the second layer provides 0.15 electrons to the adsorbate, compared to 0.38 electrons from the first layer, and in the case of ^* CHOCO, the second layer adsorbs 0.65 electron electron, which is similar to the amount provided by the first layer (0.60 electrons), and as shown in Figure 1, optimal stabilization occurs when d _s = 5 A to 6 A.

(2) Manufacture of copper particles with controlled width of atomic-scale channels

The theoretical discovery shown in Figure 1 motivated the inventors to investigate the role of atomic-scale channel width, i.e., atomic - scale inter-particle spacing. The approach we chose to create such spacings was electrochemical lithiation of CuO _x nanoparticles. This process involves the electrochemical reaction of Li ⁺ cations with CuO _x , which creates atomic-scale fractures in the particles. CuO _x nanoparticles with an average size of 50 nm were selected for lithiation. As shown in Fig. 2A, the degree of lithiation was controlled by the cell potential used in each step. Discharges were performed at 1.4 V, 1.2 V, 1 V, and 0 V, and a constant current of 10 mA · g ^-1 was used to drive the 3 V vs. Recharging was performed at Li / Li ⁺ . The spacing between CuO _x nanoparticles was controlled by stopping the lithiation process at designated points of the charge / discharge profile (FIG. 2A). The lithiated particles were then washed with water before characterization.

Changes in the CuO _x surface morphology during lithiation are shown in Figures 2b and 2c and confirmed by ex-situ transmission electron microscopy (TEM). The lithiated nanoparticles have a rugged shape and are confirmed by scanning electron microscopy (SEM) images. The same morphological changes were observed for the CuO _x particle clusters during the lithiation. The atoms in the CuO _x grain-size of the cracking level (atomic-scale crack, d _s) was determined by analysis of the TEM and STEM images (FIG. 3). Unmodified CuO _x particles with a smooth open surface consist mainly of Cu ₂ O, as detected by selected area electron diffraction (SAED). Atomic-scale surface defects such as grain boundaries were clearly generated in step I (lithiation at 1.4 V), and the defect areas defined by the yellow dotted lines shown in FIG. areas were extended in phase II (1.2 V lithiumation). After steps I and II, the oxide phase was converted to a partially reduced metal state and its surface was exposed to polycrystalline fragments < RTI ID = 0.0 > ) (Can be observed by SAED). In step III of the lithification process (lithiation at 1.0 V), the combination of atomic defects and their expansion creates ultra-micropores of angstrom size between the particles . As indicated by the yellow dotted lines, a space of between 5 Å and 6 Å was found between the crystalline grains on the reduced Cu (step III). After lithiation (step IV, lithiation at 0 V), the partially reduced Cu fragments were separated and the inter-particle distance was> 1 nm. The agglomerated particles were mostly recovered to the oxide phase after deglylation at step V (3 V recharge voltage). The phase change of the CuO _x particles generated during lithiation can be measured by powder X-ray diffraction (PXRD), X-ray absorption spectroscopy absorption spectroscopy (XAS), and X-ray photoelectron spectroscopy (XPS). The unmodified CuOx nanoparticles in FIG. 4 mainly contain Cu ₂ O and a small amount of CuO due to air exposure, and as lithiation proceeds from step I to step III, the main peak of Cu ₂ O decreases and the metal Cu peak . In step IV, only the metal Cu peak was detected after the termination of lithiation, indicating that CuO _x was completely reduced. 5A and 5B show the XANES and EXAFS spectra of the copper oxide nanoparticles obtained after each step of the lithiation process, respectively. The XANES spectrum shows that the Cu cations in the blank CuO _x are present in a monovalent oxidation state with a small amount of divalent ions, and the reduction of the copper is completed in step IV, so that the XANES spectrum is substantially identical to that of the Cu foil. Also, after step V and delithiation, the oxidation state of CuO _x was restored. The EXAFS spectrum shows that the peak of Cu-O backscattering is gradually converted to Cu-Cu backscattering until step IV, and Cu-O backscattering is restored until after step V is recovered. 6A and 6B are Cu 2p and Cu LMM spectra of each sample, and Li 1s spectrum of each sample, respectively. The oxidation state of copper gradually decreased with progressive lithiation, and no residual lithium was found after washing the lithiated sample. These techniques indicate that the oxidation state of the copper is reduced during lithiation and increased after de-lithiation, which is consistent with the information obtained in the SAED pattern of the TEM shown in Figure 2c. As confirmed by Li 1s XPS (FIG. 6b), Li ₂ O and residual lithium of the lithiated sample were completely removed by washing after each lithiation step.

The morphological change determined by analysis of the TEM image is shown in Figure 2c and the distribution of d _s values was determined by analyzing the scale of the inter-particle spacing observed in the TEM image, have. After steps I and II of the lithiation process, the value of d _s corresponds mainly to the lattice spacing for Cu and Cu ₂ O planes ( d _s = 2.08 Å and 3.01 Å, respectively). Thus, the measurements may be due to defects and / or grain boundaries rather than atomic-scale interplanar spaces. After step III, the interplanar spacing is ~ 5 A to 6 A, which corresponds to the value required to promote CC coupling, based on the DFT calculation discussed above. After complete lithiation up to step IV, the reduced Cu particles grew and their interplanar spacings increased to values between 7 A and 20 A; On the other hand, the spacing remained almost unchanged even after lithiumation up to step V. The relatively large interplanar spacing after lithiation in steps IV and V is very similar to the formation of micropores (< 20 A) in the metal oxide. In agreement with this interpretation, the pupil size distribution (Figure 7) determined from the analysis of the Brunauer-Emmett Teller (BET) isotherm shows the average size of the inter-particle spacing determined after each lithiation step by TEM analysis, Match. These results show that the lithiation of the CuO _x nanoparticles results in inter-particle spacings in the range of 3.0 A to 20 A and the preferred spacing of 5 A to 6 A (expected in the DFT calculation) The load is clearly demonstrated.

(3) On CO2RR  Catalyst activity and selectivity

The catalytic activity and selectivity for CO ₂ RR was evaluated by performing ambient-pressure CO ₂ electrolysis at constant potential for several hours. 8A shows the geometric current density of the samples of each step. About -0.9 V vs. In RHE, the samples that were lithiated up to step III exhibited a 6-fold increase in current density compared to unmodified CuO _x . It is noted that the lithiated catalyst with interplanar spacing of about 5 A to 6 A also has a large electrochemical surface area (ESA), which is the electrical double-layer capacitance , EDLC). The tendency of ESA differs from that of BET surface area. This means that when the interplanar spacing is between ~ 5 A and 6 A, the electrochemical catalytic activity is abruptly increased resulting in an abnormal increase in capacitance at a pore size of less than 10 A.

In order to minimize the pH change near the cathode, a 0.1 M CsHCO ₃ solution was used as the electrolyte and the cathode potential was -0.9 V vs. RHE &lt; / RTI &gt; The present inventors have found that hydrated Cs ^{&lt; + &} gt ^; cations can buffer pH changes that occur near the surface of the catalyst under significant electrolyte polarization conditions, thus helping to increase the amount of carbon dioxide (CO ₂ ) available for electrochemical reactions. The cathode potential is -0.9 V vs. The hydrated Cs ⁺ cations present in the outer Helmholtz layer impose a local electric field that enhances the formation of CC bonds through the coupling of adsorbed CO or adsorbed CO and HCO when exhibiting a positive value than RHE . Evidence for the absence of mass transfer efficiency (mass transfer effect) is given by the same Tafel slope is observed for the a lithiated CuO _x sample so different. Figure 8b shows the distribution of the product obtained in the lithiated electrode and unmodified copper oxide nanoparticles. As d _s increases, the formation of the C ₁ product gradually decreases while the formation of C ₂₊ products, particularly ethylene and ethanol, increases significantly. This effect is maximized at step III ( d _s = 5.2 Å), at which the C ₂ H ₄ / CH ₄ ratio increases to 54.3% and the FE of H ₂ decreases to 19%. Also, the onset potential of C ₂ H ₄ formation is -0.5 V vs.. RHE, which is about 300 mV lower than the potential of the unmodified sample. After lithiation from point d _s = 7 A to step IV, the selectivity to C ₁ product and hydrogen is restored and the FE for C ₂ H ₄ falls to the level observed after step V. FE as a function of the total applied potential is shown in Fig. 9 and product local current as a function of the total applied potential was also measured. Figure 9 shows that the samples washed after lithiation show better performance than the samples that have not been cleaned, which suggests that the residual SEI layer on the catalyst surface may interfere with the coupling reaction of CO2RR. The geometrically normalized product current density corresponds to the trend of the product current density normalized by the specific surface area (SSA).

We also note that the repeated lithiation cycles (5, 10 and 20 cycles) yield CO2RR activity similar to that obtained after step V (FIG. 10). Figure 10a shows the current density of the 5, 10, and 20 lithiated / de-lithized cycled samples, and Figure 10b shows the Faraday efficiency of each product. The catalytic activity and selectivity of the products did not change significantly after repeated cyclization cycles. The partial current density of the C _{2 +} product and -0.9 V vs. The FE of the major CO 2 RR product obtained in RHE is shown as a function of the lithiation step in Figures 8c and 8d, respectively. The maximum current density for the C _{2 +} product is observed at d _s = 5.2 Å (step III), which is approximately 12 times higher than the unmodified sample, while containing H ₂ and CO, formate, and CH ₄ The maximum current density of the C ₁ product was reduced. The high current density is attributed to both the increased electrochemically active surface area and the reduction of the free energy barrier for CO ₂ reduction.

Since the catalytic activity and selectivity are dependent on catalyst mass loading, the effect of catalyst mass loading on the selectivity for C ₂₊ products was investigated using CuO _x with d _s = 5 Å to 6 Å. The catalyst was prepared by drop-casting 50 μL to 250 μL of the catalyst-containing solution on a glassy carbon substrate. The measured activity and FE for C &lt; _{2 + & gt ;} products are shown in Figures 8e and 11. 11A shows a linear sweep voltammetry of a sample with different mass loading at a scan rate of 20 mVs &lt; ^{-1 &} gt ;, and Fig. 11B shows a sweep voltammetry of -0.8 V and -0.9 V vs. a different mass loading. The current density of the samples during the chronoamperometry at the applied voltage of RHE is shown. 11C and 11D show -0.9 V vs. &lt; RTI ID = 0.0 &gt; RHE shows the Faraday efficiency of the gaseous and liquid products according to the mass loading, and Figs. 11E and 11F show -0.8 V vs. And the Faraday efficiency of the gaseous and liquid products according to mass loading in RHE. Fig. 11g shows -0.8 V and -0.9 V vs. vs.. Shows the Faraday efficiency of the C ₂₊ product with different mass loading in RHE. Figure 8E also compares the performance of the Cu catalyst of this example with the performance of a prior art Cu catalyst operating under the same conditions. The performance of these catalysts was then evaluated (Figures 12 and 13). Figures 12a, 12b and 12c show the linear sweep voltage current method, the current density during the chrono current measurement, and the Faraday efficiency of the gaseous product at an applied voltage, respectively, at a scan rate of 20 mV · s ^-1 . 12D shows the Faraday efficiency of each liquid product according to the applied voltage, and the FE for formate and CO increases at low overvoltage. 13A shows a linear sweep voltage and current method at a scan rate of 20 mVs &lt; ^-1 &gt; for a 20 W oxygen plasma treated Cu electrode for 2 minutes, and FIG. 13B shows a linear sweep voltage &lt; Current density. 13C and 13D show the Faraday efficiency of the gaseous and liquid products according to the applied voltage, respectively. As a result, the FE of the C ₂₊ product of the prior art catalyst comprising oxide-derived Cu and O ₂ plasma-treated Cu was similar to that reported previously.

We also found that CuO _x performance of d _s = 5 Å to 6 Å shown in FIG. 8 e shows that the optimum mass loading (100 μL, corresponding to 11.4 μg Cu) is greater than the maximum FE-78% for C ₂₊ products and about 75 % Of 1-hour average FE-. In conclusion, we can conclude that the C ₂₊ FE achieved by forming atomic-scale interparticle spacings of 5 Å to 6 Å significantly exceeds those produced by other techniques .

The reactivity for CC coupling during CO2RR is consistent with the binding energy of CO at the Cu surface. The binding energy of CO was investigated by temperature-programmed desorption (TPD), the results of which are shown in FIG. In all of the lithiated samples, CO was desorbed at a relatively high temperature of ~ 200 K, whereas CO desorption from unmodified samples occurred at ~ 170 K. The lithiated sample with d _s = 5 A to 6 A (prepared in step III) shows a CO desorption peak at 300 K and a large amount of CO is released (FIG. 15). 15A and 15B show a comparison of the total amount of CO desorbed from each sample and the total amount of desorbed CO of each sample at 200 K and 300 K, respectively. A comparison of the results in Figures 15 and 8c clearly shows the correlation between the peak temperature at which CO is desorbed and the partial current density for C ₂₊ product formation. The inventors have also the maximum value of the partial current density for forming a CO desorption temperature and the C ₂₊ product can know the d _s = 5 Å to about 6 Å appears one time, which is also active, and the selection of the value of d _s catalyst Of the population. These results are also fully consistent with DFT calculations presented in Figure 1c, which shows the strongest binding energy for CO in d _s = 5 Å to about 6 Å in Figure 1c, formation CC bond when d _s = 5 Å to about 6 Å It is predicted that the speed should be higher.

The catalyst samples were all analyzed characteristics after CO2RR to determine whether any parameter other than d _s is contributing to the improved activity and selectivity of Cu to CO2RR. It was confirmed by ex-situ TEM that morphological changes after CO2RR were absent in all samples. Likewise, the size of d _s remained relatively constant after CO2RR. The stability of d _s is also reflected in the stability of the current density observed for several hours at the applied potential (Figure 16). Taking into account the Cu oxidation state and the importance of sub-surface oxygen for the activity and selectivity of Cu relative to the CO2RR, we have evaluated the post-use oxidation state of the catalyst for CO2RR. The present inventors have found that -0.9 V vs. XRD by XRD. By applying a potential of the RHE it was observed to be a CuO _x reduction as soon as metal Cu, suggesting that the CO2RR occurs in the metallic Cu. These findings are -0.9 V vs. Was confirmed by the operando XAS spectrum obtained for the applied potential of RHE. The blank samples and the XANES and EXAFS spectra of the lithiated samples up to steps I through V show -0.9 V vs. vs.. It is demonstrated that all samples after CO ₂ reduction in RHE are reduced to metallic copper phase regardless of the initial oxidation state of Cu (FIG. 17). FIG. 17A is a schematic diagram of the operando XAS analysis setup, and FIGS. 17B and 17C are -0.9 V vs. The operand XANES and operando EXAFS spectra of lithiated samples prepared by applying the reduction potential of RHE. All samples were rated at -0.9 V vs. RHE, and the operando EXAFS spectrum was reduced to -0.9 V vs.. It was confirmed that the peak of Cu-O was converted into the Cu-Cu peak under the application potential of RHE. To evaluate the possible role of minor surface oxygen not present on the bulk CuO _x , an ex-situ XPS analysis was carried out under inert gas for each sample before and after the CO2RR. Results shown in Fig. 18 is longitudinal oxidized Cu: to demonstrate that the (for example, Cu ⁺⁾ is completely reduced during CO2RR remains only a small amount of sub-surface oxygen after CO2RR (CO ₂ <10 of the O 1s signal measured before the reduction %). The present inventors also note that the tendency of selectivity for C ₂₊ products is not correlated with the intensity of the O 1s characteristic for the sub-surface oxygen, as it correlates with the value of d _s . This is because the atomic-scale space between the Cu particles plays a crucial role in determining the high selectivity for the CC coupling observed by the present inventors, and the catalyst by the surface oxygen and oxidized Cu species Lt; RTI ID = 0.0 &gt; C ₂₊ &lt; / RTI &gt; selectivity is less important. We also estimate that the amount of surface-surface oxygen estimated by ex-situ XPS analysis under an inert gas is an upper bound estimate and that the amount present under the current CO2RR condition due to the highly reducing conditions, i.e., <-0.9 V vs RHE, It will be noted that it will be less. Although there has been an attempt to estimate the amount of surface oxygen formed by removing the Cu electrode from the electrolyte, washing with water, and drying in an inert atmosphere (both without the sample being exposed to air), this protocol requires a small amount of dissolved oxygen ₂ ) and even high water affinity for Cu oxidation to surface oxidation.

Another factor that can affect the catalytic properties of Cu is the density of grain boundaries (GB). The surface densities of the GBs determined by TEM image analysis were compared and we found that the GB surface density increased in steps I and II, but the density decreased sharply in step III. Trend is the behavior of the CC coupling activity does not correspond to the surface area, GB, oxidation states, and the behavior of the defect of oxygen density of Cu, double layer capacitance (capacitance) of the expected reactivity parameters are summarized in Figure 19, depending on the value of d _s Only the same result was obtained ( d _s = 0.5 to 0.6 A). That is, the CC coupling activity of the catalyst of this example shows no correlation with the amount of surface density of GBs, and it is concluded that the size of d _s is a major factor controlling both the activity and selectivity of Cu in CO2RR .

Experimental and theoretical studies set forth herein are atoms of the interlayer spacing (interlayer spacing, d _s) between the Cu nanoparticle-solid evidence that can be used to achieve the high activity and C ₂₊ product selectivity to a level control CO2RR to provide. Our DFT calculations show that Cu (100) and Cu (111) surfaces parallel to each other at intervals of ~ 5 Å to 6 Å exhibit maximum bonding of important CO2RR intermediates to promote CC bond formation. This spacing can be created by lithiating the CuO _x nanoparticles and then removing the deposited Li ₂ O. d _s = 5 Å to Cu nanoparticles having a value of 6 Å is faraday efficiency for lithium than the Cu particles obtained from CuO _x without screen current density is increased by about 12 times or more and 78% C ₂₊ product (Faradaic efficiency ).

It will be understood by those skilled in the art that the foregoing examples of the present invention are illustrative of the present invention and that those skilled in the art can easily understand that the present invention can be easily modified into other specific forms without changing the technical ideas or essential features of the present invention will be. It is therefore to be understood that the above-described embodiments are illustrative in all respects, and are not necessarily to be construed as limitations. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims (30)

A particle, comprising an atomic-scale channel,
Wherein at least one of said atomic-scale channels is formed on a surface of said particle,
particle.
The method according to claim 1,
Wherein the width of the atomic-scale channel is less than 1 nm.
The method according to claim 1,
Wherein the inner surface of the atomic-scale channel comprised in the particles comprises a reduced metal.
The method of claim 3,
Wherein the surface between the channels in the particle comprises the reduced metal.
The method according to claim 1,
Wherein the width of the atomic-scale channel is 7 A or less.
The method according to claim 1,
Wherein the width of the atomic-scale channel is greater than or equal to 5 angstroms and less than or equal to 6 angstroms.
The method of claim 3,
Wherein the atomic-scale channel included in the particles is formed by a process comprising electrochemically lithiating the metal compound-containing particles and then delignifying the inner surface of the atomic-scale channel, And the reduced metal formed by reduction of the metal compound.
8. The method of claim 7,
Wherein the magnitude of the width of the atomic-scale channel is controlled by the cutoff voltage of electrochemically lithiating the metal compound-containing particles.
The method of claim 3,
The reduced metal may be at least one selected from the group consisting of Mg, Al, Au, Ag, Cd, Co, Cr, Cu, In, Ir, Mo, Nb, Ni, Os, Pd, Pt, Rh, Ru, Sn, Ti, And at least one metal selected from Sc, Y, Zr, Hf, Ta, Mn, Fe, Tc and Re.
The method according to claim 1,
Wherein the volume density of said atomic-scale channel is in the range of 0.01 to 0.2 per unit volume of said particles.
A catalyst comprising particles comprising an atomic-scale channel according to claim 1,
Wherein at least one of said atomic-scale channels is formed on the surface, or on the surface and inside of said particle,
Wherein the inner surface of the atomic-scale channel comprised in the particles comprises a reduced metal.
catalyst.
12. The method of claim 11,
Wherein the surface between the channels in the particle comprises the reduced metal.
12. The method of claim 11,
Wherein the width of the atomic-scale channel is less than 1 nm.
12. The method of claim 11,
Wherein the particles serve as a catalyst for the reduction of the oxygen atom-containing material.
15. The method of claim 14,
Wherein the oxygen atom-containing material comprises carbon dioxide, sulfur oxides (SO _x ), or nitrogen oxides (NO _x ).
15. The method of claim 14,
Wherein the reduction is performed by electrochemical reduction.
12. The method of claim 11,
Wherein the activity, selectivity, or activity and selectivity of the catalyst is controlled by the magnitude of the width of the atomic-scale channel contained in the particles.
15. The method of claim 14,
Wherein the width of the atomic-scale channel before and after the reduction reaction with the catalyst is kept constant.
12. The method of claim 11,
Wherein the width of the atomic-scale channel is 7 A or less.
12. The method of claim 11,
Wherein the width of the atomic-scale channel is greater than or equal to 5 angstroms and less than or equal to 6 angstroms.
12. The method of claim 11,
The reduced metal may be at least one selected from the group consisting of Mg, Al, Au, Ag, Cd, Co, Cr, Cu, In, Ir, Mo, Nb, Ni, Os, Pd, Pt, Rh, Ru, Sn, Ti, And at least one metal selected from Sc, Y, Zr, Hf, Ta, Mn, Fe, Tc and Re.
12. The method of claim 11,
Wherein the volume density of said atomic-scale channel is in the range of 0.01 to 0.2 per unit volume of said particles.
16. The method of claim 15,
The width of the atomic-scale channel of the particles is 7 A or less,
_Wherein the selectivity to C ₂₊ or higher hydrocarbon products produced by carbon dioxide reduction using said particles as a catalyst is increased relative to particles without said atomic-scale channels.
24. The method of claim 23,
Wherein the width of the atomic-scale channel of the particles is greater than or equal to 5 angstroms and less than or equal to 6 angstroms.
An atomic-scale channel according to claim 1, comprising electrochemically litholytically latticing the metal compound-containing particles to form at least one atomic-scale channel on the surface, or on the surface, A method for producing particles comprising:
The magnitude of the width of the atomic-scale channel is controlled by controlling the degree of lithiation,
Wherein at least a portion of the surface or surface and interior of the metal compound is reduced during the lithiation process to form the atomic-scale channel, and the inner surface of the atomic-scale channel included in the particle comprises the reduced metal However,
/ RTI &gt;
26. The method of claim 25,
Wherein the surface between the channels in the particle comprises the reduced metal.
26. The method of claim 25,
Wherein the lithiation comprises applying a constant current and an cut-off voltage between 0 V and 3 V or less using an electrochemical cell.
26. The method of claim 25,
Wherein a width of the atomic-scale channel included in the particle is controlled by a cut-off voltage of the electrochemical lithiumation process.
26. The method of claim 25,
Wherein the width of the atomic-scale channel of the particle is adjusted to less than 1 nm.
26. The method of claim 25,
The reduced metal may be at least one selected from the group consisting of Mg, Al, Au, Ag, Cd, Co, Cr, Cu, In, Ir, Mo, Nb, Ni, Os, Pd, Pt, Rh, Ru, Sn, Ti, , And at least one metal selected from Sc, Y, Zr, Hf, Ta, Mn, Fe, Tc and Re.

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