Preparation method of bimetallic atom catalyst

Abstract

The invention provides a preparation method of a bimetallic atom catalyst, which comprises the following steps: S1, transferring a metal crystal into a vacuum cavity, cleaning the surface of the metal crystal through ion etching and annealing treatment, introducing oxygen, and preparing a single-layer metal oxide carrier on the surface of the metal crystal; s2, depositing M1 atoms on the metal oxide carrier; s3, depositing an M2 atom on the metal oxide carrier at low temperature, capturing the M2 atom by the M1 anchoring site, and performing first heating treatment to obtain an M1-Ol-M2-carrier structure bimetallic atom catalyst; or S4, after the step S2, oxygen is introduced, the oxygen is dissociated at the M1 site to form an M1-Oa anchoring site, M3 atoms are deposited on the metal oxide carrier at low temperature, the M3 atoms are captured by the M1-Oa anchoring site, and then the M1-Oa-M3-carrier structure bimetallic atom catalyst is obtained through second heating treatment. The bimetallic atom catalyst which is good in atom dispersion and regular in structure is synthesized on the metal oxide carrier; meanwhile, the synthesis method has good metal adaptability and is simple and efficient.

Description

Technical Field

[0001] The present application relates to the field of catalyst technology, and in particular to a method for preparing a bimetallic atom catalyst. Background Art

[0002] Metal clusters are between the size of single atoms and nanoparticles. Their composition and structure are clear, providing a unique opportunity to study the structure-activity relationship of materials at the atomic level. They are also an important basis for people to understand macroscopic materials. Metal clusters usually present unique geometric structural characteristics, which determine their extraordinary physical and chemical properties, such as magic number phenomenon, isomerism phenomenon, quantum size effect and surface effect, and thus have attracted widespread attention, especially in the field of catalytic research. Metal clusters have high specific surface area, coordinated unsaturated atoms and unique electronic properties, and usually have high catalytic reaction activity and unique selectivity. After decades of development, people have found that metal clusters have excellent catalytic activity in many important chemical reactions such as coupling, oxidation and hydrogenation. As the simplest member of the metal cluster family, bimetallic atomic clusters take into account the advantages of atom economy, adjustable electronic structure and highly adaptable active sites. They are the preferred model for studying catalyst synthesis methodology, structure-activity relationship and microscopic catalytic mechanism, and have great application prospects in actual catalysis.

[0003] The precise synthesis of bimetallic atomic clusters is the foundation and core of all studies on the properties of bimetallic atoms. However, due to the short development time of bimetallic atomic clusters, the current synthesis method of bimetallic atomic catalysts is single, mainly mixing two metal salts with a carrier precursor and pyrolyzing the mixture at high temperature to obtain a bimetallic atomic catalyst. This method has uncertainty and cannot accurately control the position of the metal and the interaction between metals. Compared with the method of preparing complex carriers to stabilize bimetallic atomic clusters, the direct synthesis of metal oxide-supported diatomic catalysts has higher practical value.

[0004] Therefore, how to accurately prepare bimetallic atomic catalysts with good atomic-level dispersion and regular structure on oxides has become a difficult problem that needs to be solved urgently in this field. Summary of the invention

[0005] The purpose of the present application is to provide a method for preparing a bimetallic atom catalyst, so as to simplify the preparation method and at the same time ensure that the atoms of the prepared bimetallic atom catalyst are well dispersed and have a regular structure.

[0006] The first aspect of the present application provides a method for preparing a bimetallic atom catalyst, which comprises: S1. introducing a metal crystal into a vacuum chamber, cleaning the surface of the metal crystal by ion etching and then annealing, introducing oxygen, and preparing a single-layer metal oxide carrier on the surface of the metal crystal; S2. depositing M1 atoms on the metal oxide carrier by an electron beam evaporation source; S3. depositing M2 atoms on the metal oxide carrier at a low temperature by an electron beam evaporation source, wherein the M2 atoms are captured by the M1 anchoring points, and then performing a first heating treatment to obtain M 1- O l- M2-support structured bimetallic atom catalyst; or S4. After step S2, oxygen is introduced, and oxygen dissociates at the M1 site to form M1-O a Anchoring point, using electron beam evaporation source to deposit M3 atoms on the metal oxide support at low temperature, M3 atoms are M1-O a The anchor point is captured, and then M1-O is obtained through the second heating treatment. a -M3-support structured bimetallic atom catalyst.

[0007] In one embodiment of the present application, the metal oxide carrier is selected from at least one of zinc oxide, aluminum oxide, gallium oxide, indium oxide, and ferrosoferric oxide; the M1 and M3 atoms are each independently selected from at least one of Cr, Mn, Fe, Co or Ni; and the M2 atom is selected from at least one of Cr, Mn, Fe, Co, Ni or Pd.

[0008] In one embodiment of the present application, in step S1, the ion etching gas is argon gas, which is bombarded on the surface of the metal crystal after a high voltage of 1KV to 2KV, and then a first annealing is performed. The first annealing temperature is 673K ​​to 723K, and the first annealing time is 15mins to 25mins to restore the surface of the metal crystal; the oxygen gas pressure is 1.0×10 -8 mbar to 1.5×10 -8 mbar, the introduction time is 8 minutes to 20 minutes, when oxygen is introduced, the temperature of the metal crystal is maintained at 373K to 573K; after the oxygen is introduced, the second annealing is carried out, the second annealing temperature is 373K to 573K, and the second annealing time is 8 minutes to 12 minutes.

[0009] In one embodiment of the present application, in step S2, when the M1 atom is selected from one of Cr, Mn, Fe, and Ni atoms, the temperature of the metal oxide carrier during the deposition of the M1 atom is 373K to 573K; when the M1 atom is selected from Co atoms, the temperature of the metal oxide carrier during the deposition of the M1 atom is 473K to 673K.

[0010] In one embodiment of the present application, in step S3, the low-temperature deposition temperature of the M2 atoms is 4.2K to 120K, the first heating temperature is 200K to 300K, and the holding time is 10 minutes to 20 minutes.

[0011] In one embodiment of the present application, in step S4, the oxygen gas pressure is 1.0×10 -8 mbar to 1.5×10 -8 mbar, the introduction time is 8 minutes to 10 minutes, the temperature of the metal oxide carrier when oxygen is introduced is 273K to 473K, and the holding time is 5 minutes to 15 minutes; the low-temperature deposition temperature of M3 atoms is 4.2K to 300K, the second heating temperature is 373K to 573K, and the holding time is 15 minutes to 25 minutes.

[0012] Beneficial effects of this application:

[0013] The present application provides a method for preparing a bimetallic atom catalyst, which comprises: S1. introducing a metal crystal into a vacuum chamber, cleaning the surface of the metal crystal by ion etching and then annealing, introducing oxygen, and preparing a single-layer metal oxide carrier on the surface of the metal crystal; S2. depositing M1 atoms on the metal oxide carrier by an electron beam evaporation source; S3. depositing M2 atoms on the metal oxide carrier at a low temperature by an electron beam evaporation source, wherein the M2 atoms are captured by the M1 anchoring points, and then performing a first heating treatment to obtain M 1- O l- M2-support structured bimetallic atom catalyst; or S4. After step S2, oxygen is introduced, and oxygen dissociates at the M1 site to form M1-O a Anchoring point, using electron beam evaporation source to deposit M3 atoms on the metal oxide support at low temperature, M3 atoms are M1-O a The anchor point is captured, and then M1-O is obtained through the second heating process. a -M3- Bimetallic atom catalyst with a carrier structure. The present application provides a method for preparing a bimetallic atom catalyst, which can be precisely synthesized on a metal oxide carrier with good atomic dispersion and regular structure by kinetic control, and is easy to characterize; at the same time, the synthesis method has good metal adaptability and is simple and efficient, environmentally friendly, and can be synthesized in batches.

[0014] Of course, implementing any product or method of the present application does not necessarily require achieving all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0016] Figure 1 A schematic diagram of the preparation method of the present application;

[0017] Figure 2 This is a single-atom STM image of Mn replacing Cu atoms in the metal oxide support CuO in Example 1 of the present application;

[0018] Figure 3 The Mn-O prepared in Example 1 of the present application l -STM image of bimetallic atom catalyst with Mn-CuO support structure;

[0019] Figure 4 The Fe atom STM image of the Cu atom in the metal oxide support CuO substituted in Example 2 of the present application;

[0020] Figure 5 The Fe-O prepared in Example 2 of the present application a -STM image of bimetallic atom catalyst with Fe-CuO support structure;

[0021] Figure 6 The Fe-O prepared in Example 3 of the present application l -STM image of bimetallic atom catalyst with Fe-CuO support structure;

[0022] Figure 7 The Co-O prepared in Example 4 of the present application l -STM image of bimetallic atom catalyst with Fe-CuO support structure;

[0023] Figure 8 The Fe-O prepared in Example 5 of the present application l -STM image of bimetallic atom catalyst with Pd-CuO support structure;

[0024] Fig. 9 The Ni-O prepared in Example 6 of the present application l -STM image of bimetallic atom catalyst with Pd-CuO support structure;

[0025] Fig.10 The Co-O prepared in Example 7 of the present application l -STM image of bimetallic atom catalyst with Mn-CuO support structure;

[0026] Fig.11 The Fe-O prepared in Example 8 of the present application a -STM image of bimetallic atom catalyst with Ni-CuO support structure;

[0027] Fig.12 The Fe-O prepared in Example 9 of the present application a -STM image of the bimetallic atom catalyst with Co-CuO support structure;

[0028] Fig.13 The Mn-O prepared in Example 10 of the present application a -STM image of bimetallic atom catalyst with Mn-CuO support structure;

[0029] Fig.14 The Cr-O prepared in Example 11 of the present application a -STM image of bimetallic atom catalyst with Cr-CuO support structure;

[0030] Fig.15 The Ni-O prepared in Example 12 of the present application l -STM image of bimetallic atom catalyst with Ni-CuO support structure;

[0031] Fig.16 The Co-O prepared in Example 7 of the present application l -STM image of the product of the bimetallic atom catalyst supported by Mn-CuO during the catalytic O2 thermal dissociation reaction;

[0032] Fig.17 For this application Fig.16 nc-AFM image of the position corresponding to the white box in the middle;

[0033] Fig.18 This is an STM image of the catalyst metal state single atom Mn prepared in Comparative Example 2 of the present application, which does not change after the introduction of O2;

[0034] Fig.19 This is an STM image of the catalyst cationic state single atom Co prepared in Comparative Example 2 of the present application, which does not change after the introduction of O2;

[0035] Fig. 20 The Ni-O prepared in Example 12 of the present application l -STM image of the product of the Ni-CuO-supported bimetallic atom catalyst during the catalytic CO2 thermal dissociation reaction;

[0036] Fig.21 For this application Fig. 20 nc-AFM image of the position corresponding to the white box in the middle;

[0037] Fig. 22 This is an STM image of the catalyst prepared in Comparative Example 1 of the present application, which shows no change during the catalytic CO2 thermal dissociation reaction;

[0038] Fig.23 The Ni-O prepared in Example 12 of the present application l -The infrared reflection absorption spectrum (IRAS) of the products of the bimetallic atom catalyst with a Ni-CuO carrier structure and the catalyst prepared in comparative example 1 after catalyzing the CO2 thermal dissociation reaction is compared. DETAILED DESCRIPTION

[0039] The following will be combined with the embodiments of the present application and the accompanying drawings to clearly and completely describe the technical solutions in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art based on the present application belong to the scope of protection of the present application.

[0040] The first aspect of the present application provides a method for preparing a bimetallic atom catalyst, which comprises: S1. introducing a metal crystal into a vacuum chamber, cleaning the surface of the metal crystal by ion etching and then annealing, introducing oxygen, and preparing a single-layer metal oxide carrier on the surface of the metal crystal; S2. depositing M1 atoms on the metal oxide carrier using an electron beam (E-beam) evaporation source; S3. depositing M2 atoms on the metal oxide carrier at a low temperature using an E-beam evaporation source, wherein the M2 atoms are captured by the M1 anchoring points, and then performing a first heating treatment to obtain M 1- O l -M2-support structured bimetallic atom catalyst, O l Indicates that the O atom is lattice O in the metal oxide support; or S4. After step S2, oxygen is introduced, and oxygen dissociates at the M1 site to form M1-O a Anchoring point, using E-beam evaporation source to deposit M3 atoms on the metal oxide support at low temperature, M3 atoms are a The anchor point is captured, and then M1-O is obtained through the second heating treatment. a -M3-support structured bimetallic atom catalyst, O a The O atom represents the adsorbed O from the dissociation of the introduced oxygen. The present application provides a method for preparing a bimetallic atom catalyst, such as Figure 1As shown, a bimetallic atom catalyst with good atomic dispersion and regular structure is precisely synthesized on a metal oxide support by kinetic control. It is easy to characterize and has more than one adsorption site, which can optimize the interaction between the reactants or intermediates and the catalytic active center, so that the bimetallic atoms as active sites can perform synergistic catalysis, increase the reaction rate and selectivity, and thus improve the overall catalytic performance. At the same time, the synthesis method has good metal adaptability and is simple, efficient, environmentally friendly, and can be synthesized in batches.

[0041] In some embodiments of the present application, when the bimetallic atom catalyst is an M1-O1-M2-support structure, the number of M1 atoms is the same as the number of M2 atoms; a -M3- carrier structure, the number of M1 atoms is the same as the number of M3 atoms.

[0042] In one embodiment of the present application, the metal oxide carrier is selected from at least one of zinc oxide, aluminum oxide, gallium oxide, indium oxide, and ferroferric oxide. Preferably, the metal oxide carrier is selected from copper oxide; M1 and M3 atoms are each independently selected from at least one of Cr, Mn, Fe, Co or Ni; M2 atoms are selected from at least one of Cr, Mn, Fe, Co, Ni or Pd. Complex carriers usually introduce additional variables, which is not conducive to in-depth research on catalytic mechanisms and also poses great challenges to the design of actual catalytic systems. In the present application, M1, M2, and M3 atoms are selected from the above materials. In steps S2 and S3, M1 atoms replace metal atoms in the metal oxide carrier to form anchor points M1 on the surface of the metal crystal; in step S4, when oxygen is introduced, M1 (except Co) can dissociate oxygen to form anchor points M1-O a The above anchoring sites can accurately capture the freely migrating M2 or M3 atoms after low-temperature deposition, which is helpful for the precise synthesis of bimetallic atomic catalysts with good atomic dispersion and regular structure.

[0043] In the present application, when the bimetallic atom catalyst is M1-O l -M2-support structure, the M1 atom is selected from at least one of Cr, Mn, Fe, Co or Ni; when the bimetallic atom catalyst is M1-O a In the case of the -M3-support structure, the M1 atom is selected from at least one of Cr, Mn, Fe or Ni.

[0044] In one embodiment of the present application, in step S1, the ion etching gas is argon gas, which is bombarded on the surface of the metal crystal after a high voltage of 1KV to 2KV, and then a first annealing is performed. The first annealing temperature is 673K ​​to 723K, and the first annealing time is 15mins to 25mins to restore the surface of the metal crystal; the oxygen gas pressure is 1.0×10-8 mbar to 1.5×10 -8 mbar, the introduction time is 8 minutes to 20 minutes, when oxygen is introduced, the temperature of the metal crystal is maintained at 373K to 573K; after the oxygen is introduced, the second annealing is performed, the second annealing temperature is 373K to 573K, and the second annealing time is 8 minutes to 12 minutes. The second annealing temperature is the same as the temperature at which the metal crystal is maintained when oxygen is introduced. For example, the high voltage may be 1 KV, 1.1 KV, 1.2 KV, 1.3 KV, 1.4 KV, 1.5 KV, 1.6 KV, 1.7 KV, 1.8 KV, 1.9 KV, 2.0 KV or a range consisting of any two of them; the first annealing temperature may be 673 K, 683 K, 693 K, 703 K, 713 K, 723 K or a range consisting of any two of them; the first annealing time may be 15 mins, 16 mins, 18 mins, 20 mins, 22 mins, 24 mins, 25 mins or a range consisting of any two of them; the oxygen inlet pressure may be 1.0×10 -8 mbar, 1.2×10 -8 mbar, 1.4×10 -8 mbar, 1.5×10 -8 mbar or a range consisting of any two of the values ​​thereof; the introduction time may be 8 mins, 10 mins, 12 mins, 14 mins, 16 mins, 18 mins, 20 mins or a range consisting of any two of the values ​​thereof; when oxygen is introduced, the temperature of the metal crystal may be 373 K, 403 K, 423 K, 453 K, 483 K, 503 K, 523 K, 553 K, 573 K or a range consisting of any two of the values ​​thereof; the second annealing temperature may be 373 K, 393 K, 413 K, 433 K, 453 K, 473 K, 493 K, 513 K, 533 K, 553 K, 573 K or a range consisting of any two of the values ​​thereof; the second annealing time may be 8 mins, 9 mins, 10 mins, 11 mins, 12 mins or a range consisting of any two of the values ​​thereof. By adjusting the process parameters of step S1 within the scope of the present application, surface impurities of the metal crystal can be removed to obtain a large-scale metal crystal surface, which is then oxidized by an appropriate amount of oxygen, which is beneficial to the preparation of a single-layer metal oxide carrier on the metal crystal surface.

[0045] In one embodiment of the present application, in step S2, when the M1 atom is selected from one of Cr, Mn, Fe, and Ni atoms, the temperature of the metal oxide carrier during the deposition of the M1 atom is 373K to 573K; when the M1 atom is selected from Co atoms, the temperature of the metal oxide carrier during the deposition of the M1 atom is 473K to 673K. For example, when M1 atom is selected from one of Cr, Mn, Fe, and Ni atoms, the temperature of the metal oxide support when M1 atom is deposited can be 373K, 393K, 413K, 433K, 453K, 473K, 493K, 513K, 533K, 553K, 573K, or a range consisting of any two of these values; when M1 atom is selected from Co atom, the temperature of the metal oxide support when M1 atom is deposited can be 473K, 493K, 513K, 533K, 553K, 573K, 593K, 613K, 633K, 653K, 673K, or a range consisting of any two of these values. Compared with Co atom, the reaction energy barrier of Cr, Mn, Fe, and Ni atoms replacing Cu atoms in CuO is higher, so when M1 is selected from Co atom, the temperature of the metal oxide support when M1 atom is deposited is higher. Regulating the temperature of the metal oxide support during M1 atom deposition within the scope of the present application helps M1 atoms to replace metal atoms of the metal oxide support, thereby forming anchoring points on the metal crystal surface, thereby facilitating the precise synthesis of a bimetallic atom catalyst with good atomic dispersion and regular structure.

[0046] In one embodiment of the present application, in step S3, the low temperature deposition temperature of M2 atoms is 4.2K to 120K, the first heating temperature is 200K to 300K, and the holding time is 10mins to 20mins. For example, in step S3, the low temperature deposition temperature of M2 atoms can be 4.2K, 10K, 20K, 30K, 40K, 50K, 60K, 70K, 80K, 90K, 100K, 110K, 120K, or a range consisting of any two values ​​therein; the first heating temperature can be 200K, 220K, 240K, 260K, 280K, 300K, or a range consisting of any two values ​​therein; the holding time can be 10mins, 13mins, 15mins, 17mins, 19mins, 20mins, or a range consisting of any two values ​​therein. By adjusting the process parameters of step S3 within the scope of the present application, low-temperature deposition of M2 atoms on the metal oxide support helps M2 atoms diffuse on the surface of the metal oxide support, thereby being captured by the anchoring point M1, which helps to accurately synthesize M1-O with good atomic dispersion and regularity. l -M2-support structured bimetallic atom catalyst, and the structure of the bimetallic atom catalyst is stable.

[0047] In some embodiments of the present application, the bimetallic atom catalyst is M1-O l -M2- carrier structure, the number of M1 atoms in the metal oxide carrier accounts for 1% to 20%. Specifically, the number of M1 atoms refers to the ratio of the number of M1 atoms to the number of metal atoms in the surface monolayer of the metal oxide carrier. For example, the number of M1 atoms can be 1%, 5%, 10%, 15%, 20% or a range consisting of any two of these values. The bimetallic atom catalyst has the above characteristics, and the atoms of the bimetallic atom catalyst are well dispersed and the structure is regular.

[0048] In one embodiment of the present application, in step S4, the oxygen gas pressure is 1.0×10 -8 mbar to 1.5×10 -8 mbar, the introduction time is 8 mins to 10 mins, the temperature of the metal oxide support when oxygen is introduced is 273K to 473K, and the holding time is 5 mins to 15 mins; the low temperature deposition temperature of M3 atoms is 4.2K to 300K, the second heating temperature is 373K to 573K, and the holding time is 15 mins to 25 mins. For example, in step S4, the oxygen introduction pressure is 1.0×10 -8 mbar, 1.1×10 -8 mbar, 1.2×10 -8 mbar, 1.3×10 -8 mbar, 1.4×10 -8 mbar, 1.5×10 -8mbar or a range consisting of any two values ​​thereof, the introduction time is 8 mins, 8.5 mins, 9 mins, 9.5 mins, 10 mins or a range consisting of any two values ​​thereof; the temperature of the metal oxide carrier when oxygen is introduced can be 273K, 283K, 293K, 303K, 313K, 323K, 333K, 343K, 353K, 363K, 373K, 393K, 413K, 433K, 453K, 473K or a range consisting of any two values ​​thereof; the holding time can be 5 mins, 6 mins, 8 mins, 10 mins, 12 mins, 14 mins, 15 mins or a range consisting of any two values ​​thereof; M The low temperature deposition temperature of 3 atoms can be 4.2K, 10K, 20K, 40K, 60K, 80K, 100K, 120K, 140K, 160K, 180K, 200K, 220K, 240K, 260K, 280K, 300K or a range consisting of any two of them; the second heating temperature can be 373K, 393K, 413K, 433K, 453K, 473K, 493K, 513K, 533K, 553K, 573K or a range consisting of any two of them; the holding time can be 15mins, 17mins, 19mins, 20mins, 21mins, 23mins, 25mins or a range consisting of any two of them. By adjusting the process parameters of step S4 within the scope of this application, it is helpful to form M1-O after oxygen dissociates at the M1 site. a Anchor point, M3 atom is M1-O a Anchor point capture, thus obtaining M1-O a -M3-support structured bimetallic atom catalyst, and the structure of the bimetallic atom catalyst is regular and stable.

[0049] In some embodiments of the present application, in step S4, oxygen is introduced using a micro-leak valve.

[0050] In some embodiments of the present application, the bimetallic atom catalyst is M1-O a -M3- carrier structure, the number of M1 atoms in the metal oxide carrier accounts for 1% to 20%. Specifically, the number of M1 atoms refers to the ratio of the number of M1 atoms to the number of metal atoms in the surface monolayer of the metal oxide carrier. For example, the number of M1 atoms can be 1%, 5%, 10%, 15%, 20% or a range consisting of any two of these values. The bimetallic atom catalyst has the above characteristics, and the atoms of the bimetallic atom catalyst are well dispersed and the structure is regular.

[0051] In some embodiments of the present application, the first annealing rate is 10K / min to 200K / min, the second annealing rate is 10K / min to 200K / min, the first heating rate is 1K / min to 100K / min, and the second heating rate is 1K / min to 100K / min. For example, the first annealing rate may be 10 K / min, 20 K / min, 50 K / min, 80 K / min, 100 K / min, 120 K / min, 150 K / min, 180 K / min, 200 K / min, or a range consisting of any two of these values; the second annealing rate may be 10 K / min, 20 K / min, 50 K / min, 80 K / min, 100 K / min, 120 K / min, 150 K / min, 180 K / min, 200 K / min, or a range consisting of any two of these values; the first heating rate may be 1 K / min, 10 K / min, 20 K / min, 50 K / min, 80 K / min, 100 K / min, or a range consisting of any two of these values; the second heating rate may be 1 K / min, 10 K / min, 20 K / min, 50 K / min, 80 K / min, 100 K / min, or a range consisting of any two of these values.

[0052] In some embodiments of the present application, there is no particular limitation on the E-beam evaporation source, micro-leak valve, ion etching equipment, ultra-high vacuum scanning probe microscopy system, and sample heating stage, as long as the purpose of the present application can be achieved.

[0053] In some embodiments of the present application, the oxygen and metal crystals in the present application may be conventional substances that are commercially available, and there is no particular limitation on their sources, as long as the purpose of the present application can be achieved.

[0054] Example

[0055] The following examples and comparative examples are given to more specifically describe the embodiments of the present application. Various tests and evaluations were performed according to the following methods. In addition, unless otherwise specified, "parts" and "%" are based on mass.

[0056] Test methods and equipment:

[0057] Scanning Probe Microscopy (SPM) Characterization:

[0058] The prepared bimetallic atomic catalyst and the catalytic reaction products were characterized by scanning tunneling microscopy (STM) and non-contact atomic force microscopy (nc-AFM) based on an ultra-high vacuum low-temperature scanning probe microscopy system (model: Createc 105532).-10 mbar range. During STM characterization, the tip of the instrument was grounded and a scanning bias was applied to the sample during imaging. The scanning conditions were: 300 mV, 30 pA. All nc-AFM images were obtained using a tip modified with CO molecules in constant height mode (resonance frequency f0 ≈ 30.9 kHz, oscillation amplitude A ≈ 100 pm, quality factor Q ≈ 5.0 × 10 4 ).

[0059] Infrared reflection absorption spectroscopy (IRAS) characterization:

[0060] Based on a vacuum FTIR spectrometer (model: Bruker, Vertex 80v), the catalytic reaction products of the bimetallic atom catalyst prepared in the example or the catalytic reaction products of the catalyst prepared in the comparative example are characterized. A liquid nitrogen-cooled cadmium telluride detector is used to collect the reflected signal. In the transmittance mode, the collected signal is the ratio of the transmittance of the sample to the clean substrate. The "transmittance" here actually refers to the ratio of the light intensity reflected from the surface to the incident light intensity. The wavelength range is 2000cm -1 Up to 2200cm -1 All spectra were acquired at a sample temperature of 108 K with 512 scans and 2 cm -1 Resolution record.

[0061] Catalytic reaction activity test:

[0062] The catalytic reaction activity test adopts one of the steps (1) or (2):

[0063] (1) Catalyze the thermal dissociation reaction of O2:

[0064] The catalyst prepared in Example 7 or Comparative Example 2 of the present application is used to catalyze the thermal dissociation of O2. The specific reaction steps are: at 150K, react with the prepared Co-O l -Mn-CuO carrier or the catalyst prepared in Comparative Example 2 was introduced with O2 at a pressure of 1×10 -8 mbar, and the injection time was 1 min.

[0065] Catalytic O2 thermal dissociation reaction activity test:

[0066] The reaction activity of Example 7 or Comparative Example 2 for catalyzing thermal dissociation of O2 was tested by STM and nc-AFM characterization. The characterization methods of STM and nc-AFM characterization refer to "Scanning Probe Microscope (SPM) Characterization".

[0067] (2) Catalytic CO2 thermal dissociation reaction:

[0068] The catalyst prepared in Example 12 or Comparative Example 1 of the present application is used in a reaction example for catalyzing the thermal dissociation of CO2. The specific reaction steps are: 1) at 4.2K, react the prepared Ni-O l -Ni-CuO carrier or the catalyst prepared in Comparative Example 1 was introduced with CO2 at a pressure of 1×10 -8 mbar, and the passage time was 1 min; 2) the sample temperature was raised to 77 K and maintained for 10 mins; 3) the sample was further heated to 120 K and maintained for 10 mins.

[0069] Catalytic CO2 thermal dissociation reaction activity test:

[0070] The characterization was performed by STM and nc-AFM. The characterization methods of STM and nc-AFM refer to “Scanning Probe Microscope (SPM) Characterization”.

[0071] The reaction active products of the thermal dissociation of CO2 catalyzed by the catalyst prepared in Example 12 or Comparative Example 1 were characterized by infrared reflection absorption spectroscopy (IRAS) measurement. The method of infrared reflection absorption spectroscopy (IRAS) characterization is referred to "Infrared reflection absorption spectroscopy (IRAS) characterization".

[0072] Example 1

[0073] Preparation of Mn-O l -Mn-CuO support structured bimetallic atom catalyst

[0074] Prepare the following materials:

[0075] One Cu(110) single crystal; one bottle of high-purity (>99.999%) oxygen; one bottle of high-purity (>99.999%) argon; 50 mg of high-purity (>99.95%) Mn powder.

[0076] 1) The Cu(110) single crystal is introduced into a vacuum chamber, and argon ion etching and annealing are performed, with a high voltage of 1.5 kV, a first annealing temperature of 673 K, and a first annealing time of 20 mins. The treatment is continued for 3 rounds to obtain a clean Cu(110) single crystal surface;

[0077] 2) The Cu(110) single crystal is heated to 473K and oxygen is introduced at a pressure of 1×10 -8 mbar, the flow time is 10 mins, and then a second annealing is performed, the second annealing temperature is 473 K, and the second annealing time is 10 mins, to obtain a CuO carrier with a single layer of oxidation on the surface of the Cu(110) single crystal;

[0078] 3) Mn atoms were deposited on the CuO support using an E-beam evaporation source, and the CuO support temperature was 373K;

[0079] 4) The CuO carrier loaded with Mn single atoms is introduced into the cryogenic chamber for cooling, and the sample temperature is reduced to 100K;

[0080] 5) Using an E-beam evaporation source, an equal amount of Mn atoms is continuously deposited onto the cooled CuO support loaded with Mn single atoms;

[0081] 6) The sample was heated to room temperature (300K) for 10 min to obtain a regular Mn-O l -Mn-CuO support structured bimetallic atom catalyst.

[0082] Example 2

[0083] Preparation of Fe-O a -Fe-CuO support structured bimetallic atom catalyst

[0084] Prepare the following materials:

[0085] One Cu(110) single crystal; one bottle of high-purity (>99.999%) oxygen; one bottle of high-purity (>99.999%) argon; one high-purity (>99.995%) Fe rod.

[0086] 1) The Cu(110) single crystal is introduced into a vacuum chamber, and argon ion etching and annealing are performed, with a high voltage of 1.5 KV, a first annealing temperature of 673 K, and a first annealing time of 20 mins. The treatment is continued for 3 rounds to obtain a clean Cu(110) single crystal surface;

[0087] 2) The Cu(110) single crystal is heated to 473K and oxygen is introduced at a pressure of 1×10 -8 mbar, the flow time is 10 mins, and then a second annealing is performed, the second annealing temperature is 473 K, and the second annealing time is 10 mins, to obtain a CuO carrier with a single layer of oxidation on the surface of the Cu(110) single crystal;

[0088] 3) Fe atoms were deposited on the CuO support using an E-beam evaporation source, and the CuO support temperature was 373 K;

[0089] 4) Use a micro-leak valve to introduce O2 into the chamber, with a pressure of 1×10 -8 mbar, the introduction time was 10 mins, the CuO carrier temperature was 373 K when oxygen was introduced, and the temperature was kept for 10 min;

[0090] 5) Loading Fe-O a The CuO carrier of the species is introduced into the cryogenic chamber for cooling, and the sample temperature is reduced to 120K;

[0091] 6) Using E-beam evaporation source to cool the load Fe-O aThe same amount of Fe atoms continued to be deposited on the CuO support of the species;

[0092] 7) The sample was heated to 473K for a second time and kept at this temperature for 20 mins to obtain a regular Fe-O a -Fe-CuO support structured bimetallic atom catalyst.

[0093] Example 3

[0094] Preparation of Fe-O l -Fe-CuO support structured bimetallic atom catalyst

[0095] The preparation process of the CuO carrier (step 1) and step 2)) is the same as in Example 1;

[0096] 3) Fe atoms were deposited on the CuO support using an E-beam evaporation source, and the CuO support temperature was 373 K;

[0097] 4) The CuO carrier loaded with Fe single atoms is introduced into the cryogenic chamber for cooling, and the sample temperature is reduced to 120K;

[0098] 5) Using an E-beam evaporation source, an equal amount of Fe atoms is continuously deposited on the Fe single atom CuO support after the temperature is lowered;

[0099] 6) The sample was heated to 200K for 10 min to obtain a regular Fe-O l -Fe-CuO support structured bimetallic atom catalyst.

[0100] Example 4

[0101] Preparation of Co-O l -Fe-CuO support structured bimetallic atom catalyst

[0102] The preparation process of the CuO carrier (step 1) and step 2)) is the same as in Example 1;

[0103] 3) Co atoms were deposited on the CuO support using an E-beam evaporation source, and the CuO support temperature was 473K;

[0104] 4) The CuO carrier loaded with Co single atoms is introduced into the cryogenic chamber for cooling, and the sample temperature is reduced to 120K;

[0105] 5) Using the E-beam evaporation source, an equal amount of Fe atoms is continuously deposited on the cooled CuO support;

[0106] 6) The sample was heated to room temperature for 10 min to obtain a partially regular Co-O l-Bimetallic atom catalyst with Fe-CuO support structure.

[0107] Example 5

[0108] Preparation of Fe-O l -Pd-CuO support structure of bimetallic atom catalyst

[0109] The preparation process of the CuO carrier (step 1) and step 2)) is the same as in Example 1;

[0110] 3) Fe atoms were deposited on the CuO support using an E-beam evaporation source, and the CuO support temperature was 373 K;

[0111] 4) The CuO carrier loaded with Fe single atoms is introduced into the cryogenic chamber for cooling, and the sample temperature is reduced to 120K;

[0112] 5) Using an E-beam evaporation source, an equal amount of Pd atoms is continuously deposited on the cooled CuO support loaded with Fe single atoms;

[0113] 6) The sample was heated to room temperature for 10 min to obtain a partially regular Fe-O l -Pd-CuO support structured bimetallic atom catalyst.

[0114] Example 6

[0115] Preparation of Ni-O l -Pd-CuO support structure of bimetallic atom catalyst

[0116] The preparation process of the CuO carrier (step 1) and step 2)) is the same as in Example 1;

[0117] 3) Ni atoms were deposited on a CuO support using an E-beam evaporation source, and the CuO support temperature was 373 K;

[0118] 4) The CuO sample loaded with Ni single atoms is introduced into the cryogenic chamber for cooling, and the sample temperature is reduced to 120K;

[0119] 5) Using an E-beam evaporation source, an equal amount of Pd atoms is continuously deposited on the CuO support loaded with Ni single atoms after the temperature is lowered;

[0120] 6) The sample was first heated to room temperature for 10 min to obtain a partially regular Ni-O l -Pd-CuO support structured bimetallic atom catalyst.

[0121] Example 7

[0122] Preparation of Co-O l-Mn-CuO support structured bimetallic atom catalyst

[0123] The preparation process of the CuO carrier (step 1) and step 2)) is the same as in Example 1;

[0124] 3) Co atoms were deposited on the CuO support using an E-beam evaporation source, and the CuO support temperature was 473K;

[0125] 4) The CuO sample loaded with Co single atoms is introduced into the cryogenic chamber for cooling, and the sample temperature is reduced to 120K;

[0126] 5) Using an E-beam evaporation source, an equal amount of Mn atoms is continuously deposited on the cooled CuO support loaded with Co single atoms;

[0127] 6) The sample was heated to room temperature for 10 min to obtain a regular Co-O l -Mn-CuO support structured bimetallic atom catalyst.

[0128] Example 8

[0129] Preparation of Fe-O a -Bimetallic Atom Catalyst with Ni-CuO Support Structure

[0130] The preparation process of the CuO carrier (step 1) and step 2)) is the same as in Example 2;

[0131] 3) Fe atoms were deposited on the CuO support using an E-beam evaporation source, and the CuO support temperature was 373 K;

[0132] 4) Use a micro-leak valve to introduce O2 into the chamber, with a pressure of 1×10 -8 mbar, the introduction time was 10 mins, the CuO carrier temperature was 373 K when oxygen was introduced, and the temperature was kept for 10 min;

[0133] 5) Loading Fe-O a The CuO carrier of the species is introduced into the cryogenic chamber for cooling, and the sample temperature is reduced to 120K;

[0134] 6) Using E-beam evaporation source to cool the load Fe-O a The same amount of Ni atoms continued to be deposited on the CuO support of the species;

[0135] 7) The sample was heated to 473K for a second time and kept at this temperature for 20 mins to obtain a partially regular Fe-O a -Bimetallic atom catalyst with Ni-CuO support structure.

[0136] Example 9

[0137] Preparation of Fe-O a -Co-CuO support structured bimetallic atom catalyst

[0138] The preparation process of the CuO carrier (step 1) and step 2)) is the same as in Example 2;

[0139] 3) Fe atoms were deposited on the CuO support using an E-beam evaporation source, and the CuO support temperature was 373 K;

[0140] 4) Use a micro-leak valve to introduce O2 into the chamber, with a pressure of 1×10 -8 mbar, the introduction time is 10mins. The CuO carrier temperature when oxygen is introduced is 373K, and the temperature is kept for 10 minutes;

[0141] 5) Loading Fe-O a The CuO carrier of the species is introduced into the cryogenic chamber for cooling, and the sample temperature is reduced to 120K;

[0142] 6) Using E-beam evaporation source to cool the load Fe-O a The same amount of Co atoms continued to be deposited on the CuO support of the species;

[0143] 7) The sample was heated to 473K for a second time and kept at this temperature for 20 mins to obtain a partially regular Fe-O a -Dual metal atom catalyst with Co-CuO support structure.

[0144] Example 10

[0145] Preparation of Mn-O a -Mn-CuO support structured bimetallic atom catalyst

[0146] The preparation process of the CuO carrier (step 1) and step 2)) is the same as in Example 2;

[0147] 3) Mn atoms were deposited on the CuO support using an E-beam evaporation source, and the CuO support temperature was 373K;

[0148] 4) Use a micro-leak valve to introduce O2 into the chamber, with a pressure of 1×10 -8 mbar, the introduction time is 10mins. The CuO carrier temperature when oxygen is introduced is 373K, and the temperature is kept for 10 minutes;

[0149] 5) Loading Mn-O a The CuO carrier of the species is introduced into the cryogenic chamber for cooling, and the sample temperature is reduced to 120K;

[0150] 6) Using E-beam evaporation source to cool down the load Mn-O aThe same amount of Mn atoms continued to be deposited on the CuO support of the species;

[0151] 7) The sample was heated to 473K for a second time and kept at this temperature for 20 mins to obtain a regular Mn-O a -Mn-CuO support structured bimetallic atom catalyst.

[0152] Embodiment 11

[0153] Preparation of Cr-O a -Bimetallic Atom Catalyst with Cr-CuO Support Structure

[0154] The preparation process of the CuO carrier (step 1) and step 2)) is the same as in Example 2;

[0155] 3) Using an E-beam evaporation source to deposit Cr atoms on a CuO carrier, the CuO carrier temperature is 373K;

[0156] 4) Use a micro-leak valve to introduce O2 into the chamber, with a pressure of 1×10 -8 mbar, the introduction time is 10mins. The CuO carrier temperature when oxygen is introduced is 373K, and the temperature is kept for 10 minutes;

[0157] 5) Loading Cr-O a The CuO carrier of the species is introduced into the cryogenic chamber for cooling, and the sample temperature is reduced to 120K;

[0158] 6) Using E-beam evaporation source to cool down the load with Cr-O a The same amount of Cr atoms continued to be deposited on the CuO support of the species;

[0159] 7) The sample was heated to 473K for a second time and kept at this temperature for 20 mins to obtain a partially regular Cr-O a -Bimetallic atom catalyst with Cr-CuO support structure.

[0160] Example 12

[0161] Preparation of Ni-O l -Bimetallic Atom Catalyst with Ni-CuO Support Structure

[0162] The preparation process of the CuO carrier (step 1) and step 2)) is the same as in Example 1;

[0163] 3) Ni atoms were deposited on a CuO support using an E-beam evaporation source, and the CuO support temperature was 373 K;

[0164] 4) The CuO sample loaded with Ni single atoms is introduced into the cryogenic chamber for cooling, and the sample temperature is reduced to 120K;

[0165] 5) Using an E-beam evaporation source, an equal amount of Ni atoms are continuously deposited on the CuO support loaded with Ni single atoms after the temperature is lowered;

[0166] 6) The sample was heated to room temperature for 10 min to obtain a regular Ni-O l -Bimetallic atom catalyst with Ni-CuO support structure.

[0167] Comparative Example 1

[0168] The preparation method of the present application is not used to prepare Ni-O l -Ni catalyst, directly depositing metal atoms on a monolayer of oxidized CuO in one step will obtain a metallic single-atom Ni catalyst (Ni m ) and cationic single-atom Ni catalysts (Ni c ), specifically:

[0169] 1) The Cu(110) single crystal is introduced into a vacuum chamber, and argon ion etching and annealing are performed, with a high voltage of 1.5 kV, a first annealing temperature of 673 K, and a first annealing time of 20 mins. The treatment is continued for 3 rounds to obtain a clean Cu(110) single crystal surface;

[0170] 2) The Cu(110) single crystal is heated to 473K and oxygen is introduced at a pressure of 1×10 -8 mbar, the flow time is 10 mins, and then a second annealing is performed, the second annealing temperature is 473 K, and the second annealing time is 10 mins, to obtain a CuO carrier with a single layer of oxidation on the surface of the Cu(110) single crystal;

[0171] 3) Using an E-beam evaporation source to deposit Ni atoms on a CuO carrier at a temperature of 200 K, a metallic single-atom Ni catalyst (Ni m ) and cationic single-atom Ni catalysts (Ni c ), i.e. Ni m and Ni c / CuO support structure catalyst.

[0172] Comparative Example 2

[0173] The preparation method protected by this application is not used to prepare Co-O l -Mn catalyst, directly depositing metal atoms on a monolayer of oxidized CuO in one step will produce a metallic single-atom Mn catalyst (Mn m ) and cationic single-atom Co catalysts (Co c ), specifically:

[0174] 1) The Cu(110) single crystal is introduced into a vacuum chamber, and argon ion etching and annealing are performed, with a high voltage of 1.5 kV, a first annealing temperature of 673 K, and a first annealing time of 20 mins. The treatment is continued for 3 rounds to obtain a clean Cu(110) single crystal surface;

[0175] 2) The Cu(110) single crystal is heated to 473K and oxygen is introduced at a pressure of 1×10 -8 mbar, the introduction time is 10 mins, and then a second annealing is performed, the second annealing temperature is 473 K, the second annealing time is 10 mins, and a CuO carrier with a single layer of oxidation on the surface of the Cu(110) single crystal is obtained;

[0176] 3) Using an E-beam evaporation source to deposit Co atoms on a CuO support at a temperature of 473 K, a cationic single-atom Co catalyst (Co c );

[0177] 4) Using an E-beam evaporation source to deposit Mn atoms on a CuO support at a temperature of 200 K, a metallic single-atom Mn catalyst (Mn m ).

[0178] The structural parameters and performance parameters of the above embodiments and comparative examples are shown in Table 1 and Table 2.

[0179] Table 1

[0180]

[0181] Table 2

[0182]

[0183]

[0184] It can be seen from Examples 1 to 12 and Comparative Examples 1 to 2 that the bimetallic atom catalyst prepared by the preparation method of the bimetallic atom catalyst provided by the present application has a relatively regular structure, good atomic dispersion, and good catalytic reaction activity. Among them, the structural regularity of Examples 4 to 6, Example 9 and Example 11 refers to the presence of unpaired single atoms in the bimetallic atom catalyst in addition to the bimetallic atoms. The structural regularity of Example 8 refers to the presence of unpaired single atoms in the bimetallic atom catalyst in addition to the target bimetallic atom catalyst Fe-O a -The presence of unpaired single atoms and non-target diatomic Fe-O outside the Ni-CuO support structure a -Fe.

[0185] Example 1: Mn-O l-Mn bimetallic atom catalyst, Mn single atoms deposited on CuO support such as Figure 2 As shown in the figure,

[110] and

[001] are different crystal directions on the CuO (110) crystal plane. Mn single atoms replace the Cu atoms in the -Cu-O- chain on the single-layer CuO support to form regular Mn single atom anchoring points. l -Mn-CuO support structure of the bimetallic atom catalyst such as Figure 3 As shown in the figure, after room temperature (300K), the oxygen atoms in the -Cu-O- chain bridge the Mn-O l -Mn bimetallic atomic clusters, wherein the oxygen atoms come from the oxygen in the CuO carrier. l -The bimetallic atom catalyst with a Mn-CuO carrier structure undergoes a temperature increase during the preparation process and is maintained for a certain period of time. Therefore, the bimetallic atom catalyst has the ability to maintain its structure and properties unchanged, that is, thermodynamic stability; at the same time, the structure of the bimetallic atom catalyst synthesized on the metal oxide carrier is highly dispersed and regular, and the structure of the synthesized bimetallic atom catalyst is almost identical.

[0186] Example 2 Preparation of Fe-O a -Fe-CuO support structure of the bimetallic atom catalyst process, the Fe single atom deposited on the CuO support such as Figure 4 As shown in the figure, the Fe single atom replaces the Cu atom in the -Cu-O- chain on the single-layer CuO support to form a regular Fe single atom anchoring point; the prepared Fe-O a -Fe-CuO support structure of the bimetallic atom catalyst such as Figure 5 As shown in the figure, when O2 is introduced into the CuO carrier at a temperature of 373K, O2 is adsorbed on the Fe single atom site and dissociates into O atoms under the joint action of the Fe atom and the Cu atom in the adjacent Cu(110) single crystal. The Fe-O bond formed by the O atom chemically adsorbed on the Fe single atom a Anchor point, cooled to 120K with Fe-O a The Fe atoms continue to deposit on the anchoring points, diffuse on the surface of the CuO support and are a Anchor point capture, after the second heating at 473K, the thermodynamically stable Fe-O bridged by O atoms is formed. a -Fe bimetallic atomic clusters, and the prepared Fe-O a -The bimetallic atom catalyst with Fe-CuO support structure is highly dispersed and has regular structure, and the structure of the synthesized bimetallic atom catalyst is almost identical.

[0187] like Figure 6 As shown, the Fe-O prepared in Example 3 l-Fe-CuO support structure of the bimetallic atom catalyst with good atomic dispersion and regular structure; Figure 7 As shown, the Co-O prepared in Example 4 l -Fe-CuO support structure of the bimetallic atom catalyst with good atomic dispersion and regular structure; Figure 8 As shown, the Fe-O prepared in Example 5 l -Pd-CuO support structure of the bimetallic atom catalyst with good atomic dispersion and regular structure; Fig. 9 As shown, the Ni-O prepared in Example 6 l -Pd-CuO support structure of the bimetallic atom catalyst with good atomic dispersion and regular structure; Fig.10 As shown, the Co-O prepared in Example 7 l -Mn-CuO support structure of the bimetallic atom catalyst has good atomic dispersion and regular structure; Fig.11 As shown, the Fe-O prepared in Example 8 a -The bimetallic atom catalyst with Ni-CuO support structure has good atomic dispersion and regular structure; Fig.12 As shown, the Fe-O prepared in Example 9 a -The bimetallic atom catalyst with Co-CuO support structure has good atomic dispersion and regular structure; Fig.13 As shown, the Mn-O prepared in Example 10 a -Mn-CuO support structure of the bimetallic atom catalyst has good atomic dispersion and regular structure; Fig.14 As shown, the Cr-O prepared in Example 11 a -The bimetallic atom catalyst with Cr-CuO support structure has good atomic dispersion and regular structure; Fig.15 As shown, the Ni-O prepared in Example 12 l -The bimetallic atom catalyst with Ni-CuO carrier structure has good atomic dispersion and regular structure.

[0188] like Fig.16 and Fig.17 As shown, the Co-O prepared in Example 7 of the present application l -The metal diatomic catalyst with Mn-CuO support structure can catalyze the thermal dissociation of O2. l After dissociation on -Mn, the product is adsorbed on Co-O l -Two oxygen atoms on Mn; Fig.18 and Fig.19 As shown, the metallic single-atom Mn catalyst (Mn m ) and cationic single-atom Co catalysts (Co c) has not undergone any changes, and the single cationic Co atom and metallic Mn atom do not have the ability to chemically adsorb and dissociate O2.

[0189] In the process of catalyzing the thermal dissociation of CO2 by the catalyst prepared in Example 12, CO2 was introduced, and the CO2 molecules were physically adsorbed between the -Cu-O- chains of the CuO carrier in Example 12. When the sample temperature was raised to 77K, the CO2 molecules diffused on the CuO surface and approached the Ni-O l -Ni clusters, CO2 molecules chemically adsorbed on Ni-O l -Ni atoms in the cationic state of the Ni cluster (Ni c ), the sample is further heated to 120K, CO2 molecules in Ni-O l -Ni clusters, and the dissociation products are adsorbed on Ni-O l -O species on Ni and CO molecules adsorbed on the surface of CuO support. Fig. 20 It was found that two new species appeared on the CuO surface, one of which looked similar to Ni2 clusters, but Fig.21 Additional bright spots appeared in the nc-AFM image of CuO, which were attributed to the generated O atoms. Another species could be perturbed by the CO tip on the CuO surface during STM scanning, which was attributed to the CO molecules generated by the dissociation of CO2. Fig. 22 As shown, the metallic single-atom Ni catalyst and the cationic Ni single-atom catalyst prepared in Comparative Example 1 did not undergo any changes, and the single cationic single-atom Ni and metallic single-atom Ni did not have the ability to chemically adsorb and dissociate O2.

[0190] pass Fig.23 It was found that in the IRAS spectrum, the Ni-O l -The spectrum of the bimetallic atom catalyst sample with Ni-CuO support structure shows the stretching vibration mode of CO (2105cm -1 ), which indicates that CO2 l -Ni-CuO support structure of the bimetallic atom catalyst dissociates to generate CO, while the metallic single-atom Ni catalyst and cationic single-atom Ni catalyst prepared in Comparative Example 1 do not show this feature, further confirming that CO2 dissociates to generate CO on the Ni-O l -dissociation on a bimetallic atom catalyst with a Ni-CuO support structure.

[0191] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0192] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0193] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A method for preparing a bimetallic atom catalyst, comprising: S1. introducing a metal crystal into a vacuum chamber, cleaning the surface of the metal crystal by ion etching and then annealing, introducing oxygen, and preparing a monolayer of metal oxide support on the surface of the metal crystal; S2. Depositing M1 atoms on the metal oxide support using an electron beam evaporation source; S3. Using an electron beam evaporation source to deposit M2 atoms on the metal oxide support at low temperature, the M2 atoms are captured by the M1 anchoring point, and then the M1-O is obtained by the first heating treatment. l - M2-support structured bimetallic atom catalyst; or S4. After step S2, oxygen is introduced, and the oxygen dissociates at the M1 site to form M1-O a Anchoring point, using electron beam evaporation source to deposit M3 atoms on the metal oxide support at low temperature, the M3 atoms are a The anchor point is captured, and then M1-O is obtained through the second heating process. a -M3-support structured bimetallic atom catalyst.

2. The method for preparing a bimetallic atom catalyst according to claim 1, wherein: The metal oxide carrier is selected from at least one of zinc oxide, aluminum oxide, gallium oxide, indium oxide, and ferroferric oxide; the M1 and M3 atoms are each independently selected from at least one of Cr, Mn, Fe, Co, or Ni; and the M2 atom is selected from at least one of Cr, Mn, Fe, Co, Ni, or Pd.

3. The method for preparing a bimetallic atom catalyst according to claim 1, wherein: In step S1, the ion etching gas is argon gas, which bombards the surface of the metal crystal after a high voltage of 1KV to 2KV, and then performs a first annealing, the first annealing temperature is 673K ​​to 723K, the first annealing time is 15mins to 25mins, to restore the surface of the metal crystal; The oxygen inlet pressure is 1.0×10 -8 mbar to 1.5×10 -8 mbar, the introduction time is 8 minutes to 20 minutes, and when oxygen is introduced, the temperature of the metal crystal is maintained at 373K to 573K; After the oxygen is passed through, a second annealing is performed, the second annealing temperature is 373K to 573K, and the second annealing time is 8 minutes to 12 minutes.

4. The method for preparing a bimetallic atom catalyst according to claim 1, wherein: In step S2, when the M1 atom is selected from one of Cr, Mn, Fe, and Ni atoms, the temperature of the metal oxide support during the deposition of the M1 atom is 373K to 573K; When the M1 atom is selected as Co atom, the temperature of the metal oxide carrier during the deposition of the M1 atom is 473K to 673K.

5. The method for preparing a bimetallic atom catalyst according to claim 1, wherein: In step S3, the low-temperature deposition temperature of the M2 atoms is 4.2K to 120K, the first heating temperature is 200K to 300K, and the holding time is 10 minutes to 20 minutes.

6. The method for preparing a bimetallic atom catalyst according to claim 1, wherein: In step S4, the oxygen gas pressure is 1.0×10 -8 mbar to 1.5×10 -8 mbar, the introduction time is 8 minutes to 10 minutes, the temperature of the metal oxide support when the oxygen is introduced is 273K to 473K, and the insulation time is 5 minutes to 15 minutes; The low-temperature deposition temperature of the M3 atoms is 4.2K to 300K, the second heating temperature is 373K to 573K, and the holding time is 15mins to 25mins.

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