Asymmetric light response electronic pump hydrogen production catalyst, and preparation method and application thereof

Abstract

This invention discloses an asymmetric photoresponsive electronic pump hydrogen production catalyst, its preparation method, and its application, belonging to the field of catalyst technology. The asymmetric photoresponsive electronic pump hydrogen production catalyst comprises a Ru nanocluster composite material consisting of Ru nanoclusters and a carbon-nitrogen material with Ni single atoms embedded within its lattice. ac -Ni sa / NC catalyst; the Ru ac -Ni sa In the / NC catalyst, Ni and Ru respond asymmetrically to light irradiation. Under illumination, electrons migrate from Ni to Ru, resulting in electron-rich and electron-deficient sites at Ru and Ni sites, respectively. This invention utilizes light irradiation to disrupt the equilibrium state. This asymmetric photoresponsive electron-pumped hydrogen production catalyst drives directional electron flow, maintaining the asymmetric electron distribution under light irradiation. This allows for the manipulation of photogenerated electrons and the overcoming of unfavorable reducing environments, thereby accelerating the conversion of methane and carbon dioxide into syngas.

Description

Technical Field

[0001] This invention relates to the field of catalyst technology, specifically to an asymmetric photoresponsive electronic pump hydrogen production catalyst, its preparation method, and its application. Background Technology

[0002] Carbon capture, utilization, and storage (CCUS) is a key solution to addressing environmental challenges, capturing carbon dioxide and converting it into useful products while simultaneously decarbonizing industries. Dry methane reforming (DRM) can solve the problem of converting two of the most important greenhouse gases. Its product, syngas (a mixture of CO and H2), is widely used in the petrochemical sector as a fundamental feedstock for thousands of industrial chemicals. Therefore, this reaction demonstrates strong industrial application potential and considerable social value. However, conventional thermally driven DRM typically operates at temperatures exceeding 800 °C because the high bond strength of the C=O bond (805 kJ / mol) and CH bond (434 kJ / mol) requires a significant energy consumption to achieve sufficient syngas formation rates. Furthermore, this elevated temperature promotes undesirable side reactions, including methane dehydrogenation and carbon monoxide dismutation, leading to coking and catalyst sintering, both of which result in rapid catalyst deactivation.

[0003] Solar-driven DRM represents an energy-efficient and environmentally friendly approach that promises to alter bond activation processes and overcome the inherent challenges of traditional thermally driven DRM. This process typically occurs on oxide catalysts with metal-dominant active centers, and recent studies have highlighted the indispensable role of the electronic states of these active centers in promoting reactant adsorption and subsequent activation during DRM. Researchers have proposed various strategies to design isolated active centers with customized electronic structures to enhance solar-driven DRM, but isolated active centers in the DRM reaction still struggle to achieve bimolecular activation. Preparing bimolecular active centers with asymmetric electron distributions is a highly desirable method for improving DRM performance. However, current static design strategies rely on customizing the intrinsic structure of materials to achieve thermodynamically balanced electron distributions, which face challenges in adapting to the dynamic interactions of photogenerated electrons, reducing atmospheres, and localized temperature rises in solar-driven DRM, leading to thermodynamically unfavorable asymmetric electronic configurations for maintaining the required bimolecular active centers. Therefore, there is an urgent need to develop a technology that can dynamically control electron transfer under illumination to form asymmetric electronic configurations, thereby accelerating the conversion of methane and carbon dioxide into syngas. Summary of the Invention

[0004] Therefore, the technical problem to be solved by this invention is to provide an asymmetric photoresponsive electronic pump hydrogen production catalyst, its preparation method, and its application. Under light irradiation, this Ru... ac -Ni saThe / NC catalyst drives directional electron flow, causing Ru sites and Ni sites to form electron-rich sites and electron-deficient sites respectively, maintaining an asymmetric electron distribution, thereby accelerating the conversion of methane and carbon dioxide into syngas.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] An asymmetric photoresponsive electron-pumped hydrogen production catalyst comprises a Ru nanocluster composite material consisting of Ru nanoclusters and carbon-nitrogen materials with Ni single atoms embedded within the crystal lattice. ac -Ni sa / NC catalyst, Ru nanoclusters and Ni single atoms form an interface of tightly coupled single-atom clusters through electron transfer and orbital hybridization;

[0007] The Ru ac -Ni sa In the / NC catalyst, Ni and Ru respond asymmetrically to light irradiation. Under light irradiation, electrons migrate from Ni to Ru, resulting in electron-rich sites and electron-deficient sites forming on Ru and Ni sites, respectively.

[0008] This invention involves sequentially adding Ni(NO3)2 ethanol solution and RuCl3 ethanol solution to a black solution formed by dissolving a carbon-nitrogen material (hexagonal structure) in ethanol, ultimately yielding Ru. ac -Ni sa In the NC catalyst, Ru is supported on NC in the form of nanoclusters, forming Ru-N and Ru-Ru bonds, while Ni is anchored on NC in the form of single atoms, forming Ni-N bonds. The distance between the Ru nanoclusters and Ni single atoms is 0.45~0.46 nm, forming a single-atom coupled cluster interface. That is, the Ru nanoclusters and Ni single atoms are very close, forming a tightly coupled interface through electron transfer and orbital hybridization. This interface provides the structural basis for the asymmetric response under illumination and the electron pump-driven electron transfer; thus, the Ru in this application… ac -Ni sa Unlike existing catalysts that only load Ru clusters and nickel atoms without forming chemical bonds with carbon and nitrogen materials, the / NC catalyst can induce a strong local surface plasmon resonance effect under light irradiation, while isolated nickel atoms do not have this characteristic. Therefore, it achieves an asymmetric distribution of electrons in the solar-driven DRM process.

[0009] In the aforementioned asymmetric photoresponsive electron pump hydrogen production catalyst, the distance between Ru nanoclusters and Ni single atoms is 0.45 ~ 0.46 nm; the carbon-nitrogen material has a hexagonal structure, with Ru supported on NC in the form of nanoclusters and forming Ru-N and Ru-Ru bonds; while Ni is anchored on NC in the form of single atoms to form Ni-N bonds.

[0010] A method for preparing an asymmetric photoresponsive electronic pump hydrogen production catalyst includes the following steps:

[0011] Step 1: Prepare carbonitridium materials for later use;

[0012] Step 2: Dissolve the carbon-nitrogen material prepared in Step 1 in ethanol, and disperse it thoroughly by ultrasound to obtain a black solution;

[0013] Step 3: Under heating and stirring conditions, Ni(NO3)2 ethanol solution and RuCl3 ethanol solution are added sequentially to the black solution obtained in Step 2. After continuous stirring, the solution is cooled to room temperature, centrifuged, washed, and dried to obtain a black powder.

[0014] Step 4: Heat-treat the black powder obtained in Step 3 in an inert atmosphere to obtain the above-mentioned Ru. ac -Ni sa / NC catalyst.

[0015] In the above-mentioned method for preparing an asymmetric photoresponsive electronic pump hydrogen production catalyst, step 1 involves the following preparation method for the carbon and nitrogen materials:

[0016] Step 1.1: Add zinc nitrate methanol solution dropwise to 2-methylimidazolium methanol solution to obtain a mixed solution;

[0017] Step 1.2: After stirring the mixed solution at room temperature, the resulting product is centrifuged, washed, and dried to obtain ZIF-8 powder;

[0018] Step 1.3: Calcine ZIF-8 powder in an inert atmosphere to obtain carbonitridium material.

[0019] This invention utilizes a hexagonal carbon-nitrogen material obtained by calcining ZIF-8 powder. Compared to carbon-nitrogen materials with different morphologies prepared by other methods, the hexagonal carbon-nitrogen material prepared by this method not only serves as a carrier but also actively participates in the photocatalytic process. It also exhibits higher crystallinity and fewer defects, thus significantly suppressing the recombination of photogenerated electrons and holes, extending carrier lifetime, and providing a better charge separation basis for "light-induced asymmetric response," which is beneficial for light energy capture. Simultaneously, the rough surface of this carbon-nitrogen material increases the reactive sites, exposing more uniformly distributed nitrogen coordination sites, allowing Ni single atoms to be more stably anchored and more uniformly dispersed, preventing their migration and aggregation during preparation.

[0020] In the preparation method of the above-mentioned asymmetric photoresponsive electronic pump hydrogen production catalyst, in step 1.1, the zinc nitrate methanol solution is prepared by dissolving Zn(NO3)2·6H2O in methanol, and the concentration of zinc nitrate in the zinc nitrate methanol solution is 0.05 mol / L to 0.2 mol / L.

[0021] In the preparation method of the above-mentioned asymmetric photoresponsive electronic pump hydrogen production catalyst, in step 1.1, the 2-methylimidazole methanol solution is prepared by dissolving 2-methylimidazole in methanol, and the concentration of 2-methylimidazole in the zinc nitrate methanol solution is 0.6 mol / L to 0.8 mol / L.

[0022] In the preparation method of the aforementioned asymmetric photoresponsive electronic pump hydrogen production catalyst, step 1.3 uses argon as the inert atmosphere and the calcination conditions are: heating to 980-1050℃ at a heating rate of 10℃ / min for 2 hours. This temperature range is chosen to balance the crystallinity of the support and the metal dispersion state. Since zinc nitrate is used in the precursor synthesis, and zinc has an evaporation temperature of approximately 950℃, the temperature must be higher to ensure that the carbonitridium material is free of zinc. Below this temperature, the carbonitridium material exhibits poor crystallinity and easy recombination of photogenerated carriers; above this temperature, nitrogen coordination sites are lost, Ni single atoms agglomerate, and Ru clusters over-sinter.

[0023] In the preparation method of the above-mentioned asymmetric photoresponsive electronic pump hydrogen production catalyst, in step 2, the concentration of carbon and nitrogen materials in the black solution is 1~3 g / L.

[0024] In the above-mentioned method for preparing an asymmetric photoresponsive electronic pump hydrogen production catalyst, the heating temperature in step 3 is 80℃;

[0025] The volume ratio of Ni(NO3)2 ethanol solution to RuCl3 ethanol solution is 1:2, and the concentration of Ni(NO3)2·6H2O in the Ni(NO3)2 ethanol solution is 0.01 g / mL. -1 The concentration of RuCl3·3H2O in the RuCl3 ethanol solution is 0.01 g / mL. -1 By controlling the amount of Ru and taking advantage of its metallic properties, the Ru nanoclusters formed are more stable. However, if too much RuCl3·3H2O is used, exceeding the dispersion capacity of the support, the excess Ru... 3+ During reduction, instead of forming small nanoparticles, the material agglomerates into large Ru black particles. This leads to a sharp decrease in metal utilization; that is, even with increased dosage, the catalytic activity (TOF, turnover rate) may actually decrease instead of increase. Furthermore, the solvent used in this application is ethanol. Carbon and nitrogen materials, as well as RuCl3·3H2O and Ni(NO3)2·6H2O, exhibit good dispersibility in ethanol. The moderate polarity of ethanol also allows for wetting of the material surface, forming a stable and dispersed suspension. Secondly, the evaporation temperature of ethanol is lower than that of water, facilitating subsequent drying operations.

[0026] In the preparation method of the aforementioned asymmetric photoresponsive electronic pump hydrogen production catalyst, step 4 uses argon as the inert atmosphere and the heat treatment conditions are: heating to 800 °C at a heating rate of 2 °C / min and holding for 2 hours. At a heating temperature of 800 °C, Ni... 2+ and Ru 3+ The final chemical states of single-atom Ni and Ru nanoclusters are transformed respectively. High temperature enhances the interaction between the metal and the support, allowing RuCl3 to be completely reduced and migrate to form clusters. Simultaneously, Ni is firmly anchored by nitrogen defects, maintaining single-atom dispersion, while the hexagonal structure of the carbon-nitrogen support remains stable at this temperature. If the temperature is too low (e.g., below 600℃), Ru cannot be completely reduced or migrates insufficiently, making it difficult to form clusters, and Ni may also fail to form a stable coordination structure with the support. If the temperature is too high, Ni single atoms will break free from anchorage and aggregate, and Ru clusters will become excessively sintered and larger, destroying the required "asymmetric photoresponse" structure.

[0027] The application of an asymmetric photoresponsive electronic pump hydrogen production catalyst in dry methane reforming, wherein the catalyst is prepared by the aforementioned method for preparing an asymmetric photoresponsive electronic pump hydrogen production catalyst.

[0028] The technical solution of the present invention achieves the following beneficial technical effects:

[0029] (1) In this invention, Ni(NO3)2 ethanol solution and RuCl3 ethanol solution are added sequentially to a black solution formed by dissolving carbon-nitrogen materials (hexagonal structure) in ethanol, and finally Ru is obtained. ac -Ni sa In the NC catalyst, Ru is supported on NC in the form of nanoclusters, forming Ru-N and Ru-Ru bonds, while Ni is anchored on NC in the form of single atoms, forming Ni-N bonds. The distance between the Ru nanoclusters and Ni single atoms is 0.45~0.46 nm, forming a single-atom coupled cluster interface. That is, the Ru nanoclusters and Ni single atoms are very close, forming a tightly coupled interface through electron transfer and orbital hybridization. This interface provides the structural basis for the asymmetric response under illumination and the electron pump-driven electron transfer; thus, the Ru in this application… ac -Ni sa Unlike existing catalysts that only load Ru clusters and nickel atoms without forming chemical bonds with carbon and nitrogen materials, the / NC catalyst can induce a strong local surface plasmon resonance effect under light irradiation, while isolated nickel atoms do not have this characteristic. Therefore, it achieves an asymmetric distribution of electrons in the solar-driven DRM process.

[0030] The asymmetric photoresponsive structure formed on the support enables electron localization at active sites, suppressing electron-hole recombination and promoting photoelectron transfer. Under illumination, the potential gradient drives electrons to migrate from nickel to ruthenium, resulting in the formation of adjacent electron-rich and electron-deficient sites at Ru and Ni sites, respectively. The active centers of the electron-deficient sites disrupt the tetrahedral (TD) symmetry of the methane molecule, thereby enhancing its dehydrogenation activity and forming CH4. X The active centers with electron-rich sites are conducive to the chemisorption of carbon dioxide and are activated by electron feedback to the π* antibonding orbitals, thereby enhancing reactant activation, stabilizing intermediates, and increasing syngas production.

[0031] (2) Preparation of Ru in this application ac -Ni sa When using the / NC catalyst, Ni(NO3)2 ethanol solution and RuCl3 ethanol solution are added sequentially to the black solution. The stepwise addition is to control the loading process of the metal precursor to achieve the expected differentiated structure of "Ru in clusters and Ni in single atoms". This utilizes the difference in adsorption kinetics to achieve spatial and structural separation, maintain the stability of the dispersion system, and precisely control the metal loading and sites.

[0032] Specifically, first add a Ni(NO3)2 ethanol solution, utilizing Ni... 2+ The strong coordination with the surface defect sites of carbonitridium materials allows Ni to... 2+ Ni preferentially occupies the lowest-energy and most stable anchoring sites on the carbonitridium material support. At this point, due to the absence of Ru competition, Ni can achieve atomic-level dispersion. After the addition of RuCl3 ethanol solution, due to the coordination shielding effect of chloride ions, it can only adsorb onto the remaining "weak adsorption sites" or physically deposit on the surface of the carbonitridium material support. Because these sites have weak anchoring ability, they exhibit higher migration rates during subsequent heat treatment, and Ru tends to migrate and aggregate to form clusters. If all raw materials are added at once, Ni... 2+ and Ru 3+ In solution, both Ni and Ru compete for adsorption sites on the carrier surface. Ni cannot form a pure single-atom dispersion, and Ru cannot form a uniform cluster. In the end, they tend to form Ru-Ni disordered alloys or mixed single atoms, which cannot achieve the effect of this application.

[0033] (3) The present invention uses a hexagonal carbon-nitrogen material obtained by calcining ZIF-8 powder. Compared with carbon-nitrogen materials of different morphologies prepared by other methods, the hexagonal carbon-nitrogen material prepared by this method not only serves as a carrier, but can actively participate in the photocatalytic process. It also has higher crystallinity and fewer defects, which can significantly suppress the recombination of photogenerated electrons and holes, prolong the carrier lifetime, and thus provide a better charge separation basis for "light asymmetric response", which is beneficial to light energy capture. At the same time, the rough surface of this carbon-nitrogen material increases the reactive sites of the material, that is, it can expose more uniformly distributed nitrogen coordination sites, making Ni single atoms more stable and more uniformly dispersed, avoiding their migration and aggregation during the preparation process.

[0034] (4) The asymmetric photoresponsive electron pump strategy proposed in this invention differs from the traditional strategy of achieving thermodynamic equilibrium of electron distribution by adjusting the internal structure. This photoresponsive asymmetric configuration electron pump hydrogen production catalyst utilizes light to break the equilibrium state. This asymmetric photoresponsive electron pump hydrogen production catalyst drives directional electron flow and maintains asymmetric electron distribution under light, thereby manipulating photogenerated electrons and overcoming unfavorable reducing environments.

[0035] (5) This invention constructs an asymmetric photoresponsive catalyst composed of ruthenium clusters and nickel single atoms to achieve the function of an electron pump. Under solar energy drive, this catalyst achieves a hydrogen production rate of 2.28 mol·g at 500 °C. cat -1 ·h -1 Its performance far surpasses that of other materials. Notably, its formation rate is an order of magnitude higher than that of catalysts lacking a complete electronic pump structure. Attached Figure Description

[0036] Figure 1 a and b are respectively Ru, an asymmetric photoresponsive electronic pump hydrogen production catalyst. ac -Ni sa / NC SEM images at different magnifications; c, d, e, and f are elemental distribution maps of C, N, Ru, and Ni, respectively;

[0037] Figure 2 :a is an asymmetric photoresponsive electronic pump hydrogen production catalyst Ru ac -Ni sa / NC high-magnification HAADF-STEM image; b is the intensity spectrum of the position between Ni single atoms and Ru nanoclusters; c is the Ru ac -Ni sa / NC element distribution diagram;

[0038] Figure 3 :a is Ru ac -Nisa XANES spectra of / NC, NiPc, NiO, and Ni foil at the Ni K-edge; b is Ru ac -Ni sa FT k of EXAFS spectra of / NC, NiPc and Ni foil at the Ni K edge 3 Weighted χ(k) function; c is Ru ac -Ni sa / NC and Ni foil standard samples k 3 Wavelet transform plot of weighted EXAFS spectrum; d is Ru ac -Ni sa / NC、Ru ac / NC, Ru foil, and RuO2 at the Ru K-edge; e represents Ru ac -Ni sa EXAFS spectra of / NC, RuO2, and Ru foil at the Ru K-edge FT_k 3 Weighted χ(k) function; f is Ru ac -Ni sa / NC and Ru foil standard k 3 Weighted EXAFS spectral wavelet transform plot;

[0039] Figure 4 :a is Ru ac -Ni sa / NC High-resolution XPS spectra of Ni 2p under light and dark conditions; b is Ru ac -Ni sa High-resolution XPS spectra of Ru 3p under light and dark conditions / NC;

[0040] Figure 5 The hydrogen generation rates of different materials under light-driven and thermal-driven conditions at 500 °C;

[0041] Figure 6 For Ru ac -Ni sa / NC generates apparent activation energy of H2 under both solar-driven and thermal-driven conditions. Detailed Implementation

[0042] Example 1

[0043] Asymmetric photoresponsive electronic pump Ru ac -Ni sa / NC preparation

[0044] 1.1 Preparation of NC

[0045] 2.36 g of Zn(NO3)2·6H2O was dissolved in 75 mL of methanol to obtain a zinc nitrate methanol solution; 2.63 g of 2-methylimidazole was dissolved in 45 mL of methanol to obtain a 2-methylimidazole methanol solution. The zinc nitrate methanol solution was then slowly added dropwise to the 2-methylimidazole methanol solution to obtain a mixed solution.

[0046] The mixture was stirred at room temperature for 12 hours (400 rpm) to obtain a white product. The obtained white product was centrifuged three times (8000 rpm, 10 minutes each time), washed, and then centrifuged at 80°C. o ZIF-8 powder was obtained by vacuum drying at 10 °C overnight. The ZIF-8 powder was then subjected to argon atmosphere at 10 °C. o Heating rate increased to 1000 °C / min o C, calcined for 2 hours, finally successfully synthesized NC.

[0047] 1.2, Ru ac -Ni sa / NC preparation

[0048] Weigh 0.04 g of NC and dissolve it in 20 mL of ethanol. After thorough dispersion by sonication, a black solution is obtained. Then, at 80 °C... o Under stirring, 0.3 mL of Ni(NO3)2 ethanol solution (concentration 0.01 g / mL) was added sequentially to the black solution. -1 ) and 0.6 mL of RuCl3 ethanol solution (concentration 0.01 g / mL) -1 After stirring continuously for 6 hours, the mixture was cooled to room temperature, centrifuged (13000 rpm, 20 min), washed, and then centrifuged at 80°C. o The product was dried under vacuum overnight at C to obtain a black powder. The resulting black powder was then subjected to an Ar atmosphere at 2 °C for min. -1 Heating rate to 800 o C, kept at 2 h, finally successfully synthesized Ru ac -Ni sa / NC.

[0049] Comparative Example 1

[0050] Asymmetric photoresponsive electronic pump Ru ac -Ni sa Preparation method of Al2O3:

[0051] 0.04 g of Al₂O₃ was dissolved in 20 mL of ethanol and dispersed thoroughly by ultrasonication to obtain a black solution. Subsequently, it was subjected to an 80°C test. o Under stirring, 0.3 mL of Ni(NO3)2 ethanol solution (concentration 0.01 g / mL) was added sequentially to the black solution. -1) and 0.6 mL of RuCl3 ethanol solution (concentration 0.01 g / mL) -1 After stirring continuously for 6 hours, the mixture was cooled to room temperature, centrifuged (13000 rpm, 20 min), washed, and then centrifuged at 80°C. o The product was dried under vacuum overnight at C to obtain a black powder. The resulting black powder was then subjected to an Ar atmosphere at 2 °C for min. -1 Heating rate to 800 o C, kept at 2 h, finally successfully synthesized Ru ac -Ni sa / Al2O3.

[0052] Comparative Example 2

[0053] Ru sa -Ni sa / NC preparation method

[0054] 0.04 g of NC was weighed and dissolved in 20 mL of ethanol. After thorough dispersion by ultrasonication, a black solution was obtained. Then, under stirring at 80 °C, 0.3 mL of Ni(NO3)2 ethanol solution (concentration 0.01 g / mL) was added sequentially to the black solution. -1 ) and 0.3 mL of RuCl3 ethanol solution (concentration 0.01 g / mL) -1 After stirring continuously for 6 hours, the mixture was cooled to room temperature, centrifuged (13000 rpm, 20 min), washed, and then vacuum dried at 80 °C overnight to obtain a black powder. The obtained black powder was then dried in an Ar atmosphere at 2 °C for 2 min. -1 The temperature was increased to 800℃ at a certain rate and held for 2 hours, ultimately successfully synthesizing Ru. sa -Ni sa / NC. In this comparative example, the volume ratio of Ni(NO3)2 ethanol solution to RuCl3 ethanol solution is 1:1. Compared with Example 1, the amount of RuCl3 in this comparative example is less, resulting in a lower density of Ru atoms on the support, reducing the probability of single-atom aggregation. The metal atoms are isolated from each other and thus anchored to the defects of the support. Therefore, in this comparative example, Ru and Ni both exist in the form of single atoms.

[0055] Comparative Example 3

[0056] Ni sa / NC preparation method

[0057] 0.04 g of NC was weighed and dissolved in 20 mL of ethanol. After thorough dispersion by ultrasonication, a black solution was obtained. Then, under stirring at 80 °C, 0.3 mL of Ni(NO3)2 ethanol solution (concentration 0.01 g / mL) was added to the black solution. -1The mixture was prepared by stirring continuously for 6 hours, then cooled to room temperature, centrifuged (13000 rpm, 20 min), washed, and vacuum dried at 80 °C overnight to obtain a black powder. The obtained black powder was then dried in an Ar atmosphere at 2 °C for 2 min. -1 The temperature was increased to 800 °C at a certain heating rate and held for 2 h, thus successfully synthesizing Ni. sa / NC.

[0058] Comparative Example 4

[0059] Ru ac / NC preparation method

[0060] 0.04 g of NC was weighed and dissolved in 20 mL of ethanol. After thorough dispersion by ultrasonication, a black solution was obtained. Then, under stirring at 80 °C, 0.3 mL of RuCl3 ethanol solution (concentration 0.01 g / mL) was added to the black solution. -1 After stirring continuously for 6 hours, the mixture was cooled to room temperature, centrifuged (13000 rpm, 20 min), washed, and then vacuum dried at 80 °C overnight to obtain a black powder. The obtained black powder was then dried in an Ar atmosphere at 2 °C for 2 min. -1 The temperature was increased to 800 °C at a certain rate and held for 2 h, ultimately successfully synthesizing Ru. ac / NC.

[0061] Ru prepared in Example 1 ac -Ni sa The microstructure characterization and analysis of / NC are as follows:

[0062] from Figure 1 As can be seen, the hexagonal ZIF derivatives have sharp edges and a slightly rough surface, which may be attributed to the successful anchoring of bimetallic Ru and Ni. The rough surface not only increases the reactive sites of the material but may also facilitate light energy capture. In addition, the elemental distribution map also shows that Ru is aggregated while Ni is more uniformly distributed, proving that Ru exists in clusters while Ni exists in single-atom form.

[0063] from Figure 2 The distribution of Ru clusters and Ni single atoms is clearly visible. Ni single atoms are evenly distributed around the Ru clusters, and measurements show that the distance between the clusters and single atoms is approximately 0.45 nm, indicating the formation of a single-atom coupled cluster interface. This means the Ru nanoclusters and Ni single atoms are very close, forming a tightly coupled interface through electron transfer and orbital hybridization. This interface provides the structural basis for the asymmetric response under illumination and electron pump-driven electron transfer. The elemental distribution map also clearly shows the distribution of ruthenium and nickel, proving the successful synthesis of Ru with an asymmetric structure.ac -Ni sa / NC sample.

[0064] Figure 3 The structure Ru is an asymmetric photoresponsive electronic pump structure. ac -Ni sa / NC synchrotron radiation data map, in order to reveal Ru ac -Ni sa The microelectronic structure of / NC. For Ni, X-ray absorption near-edge structure reveals its valence between 0 and 2, proving its single-atom existence. The EXAFS Fourier transform of Ni at the K-edge indicates the presence of Ni-N bonds. Wavelet transform further illustrates the presence of Ru. ac -Ni sa In / NC, Ni nanoparticles or nanoclusters are absent, existing only as single atoms. Similarly, for Ru, X-ray absorption near-edge structure reveals its valence between 0 and 4, and the addition of Ni single atoms lowers the valence of Ru. Fourier transforms of the EXAFS spectrum at the K-edge of Ru indicate the presence of Ru-N and Ru-Ru bonds. Wavelet transforms further illustrate the presence of Ru... ac -Ni sa Ru nanoclusters exist in / NC.

[0065] from Figure 4 It can be seen that under illumination, the binding energy of Ni increases from 854.7 eV to 855.2 eV, proving that the number of electrons in Ni decreases under illumination; conversely, under illumination, the binding energy of Ru decreases from 462.5 eV to 461.8 eV, proving that the number of electrons in Ru increases under illumination. These phenomena indicate that due to Ru... ac -Ni sa In / NC, the asymmetric response of Ni and Ru to light results in the formation of electron-rich sites and electron-deficient sites at Ru and Ni sites, respectively.

[0066] Ru ac -Ni sa / NC Performance Evaluation

[0067] The asymmetric photoresponsive electronic pump hydrogen production catalyst Ru prepared in Example 1 ac -Ni sa Performance tests were conducted on various samples prepared by / NC and comparative methods for producing syngas using light-driven and thermally-driven dry reforming.

[0068] The catalytic performance of the solar-driven reactor was evaluated using a custom-designed solar-driven reactor. This custom-designed quartz reactor, with a diameter of 200 mm, featured an internal annular groove with a diameter of 10 mm and a depth of 5 mm. The gas supply piping consisted of 3 mm branch pipes, and a bypass channel was specifically added for inserting thermocouples to measure the catalyst temperature. A solar simulator was used as the light source in the experiment. Before the experiment, the position of the solar-driven reactor was repeatedly adjusted to ensure that the light spot completely covered the catalyst.

[0069] During activity testing, 25 mg of each catalyst was loaded into the annular groove of the solar-driven reactor and spread evenly. First, at 500... o Under C conditions, the catalyst was reduced for 1 hour with a 20% H2 / N2 gas stream (the sample after calcination may be oxidized in air; reduction with hydrogen is used to maintain its metallic state for subsequent chemical reactions). A mixed gas (CO2 / CH4 / N2, with N2 as an internal standard) was then injected into the solar-driven reactor, with a molar ratio of CO2 / CH4 / N2 = 20 / 20 / 80. The gas flow rate was set to 120 mL / min. -1 The corresponding mass hourly space velocity is 288,000 mL gcat. -1 h -1 The catalyst surface temperature was maintained at 500°C by adjusting the light intensity of the solar simulator. o C. Thermocouples are used to monitor the reaction temperature during the reaction process.

[0070] Under thermally driven conditions, equal amounts of each catalyst are placed in a heating furnace for reaction, while all other conditions remain consistent with those under solar-driven conditions.

[0071] Figure 5 The Ru prepared according to the above embodiments is shown. ac -Ni sa A comparison of the hydrogen generation rates of / NC and various samples prepared in the comparative example under light-driven and thermal-driven conditions, and the asymmetric photoresponsive electron pump Ru ac -Ni sa The hydrogen generation rate of the / NC material under illumination is 2.28 mol·g. cat -1 ·h -1 The results far surpass those of other materials, and the hydrogen yield is nearly doubled compared to thermally driven conditions, proving that light is the cause of the excitation of the electron pump effect. The existence of the asymmetric photoresponse electron pump greatly improves the efficiency of light-driven hydrogen production.

[0072] Figure 6 Ru was shown ac -Ni saThe apparent activation energy of H2 generation by / NC under solar-driven (500 °C) and thermal-driven (500 °C) conditions. Compared to the thermal-driven condition, the apparent activation energy of H2 under light irradiation decreases from 75.6 kJ / mol to 30.8 kJ / mol, which demonstrates that Ru ac -Ni sa / NC can form more beneficial active sites for the reaction under light, thus greatly promoting the production of hydrogen.

[0073] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. An asymmetric photoresponsive electronic pump hydrogen production catalyst, characterized in that, Including Ru, which is a composite material consisting of Ru nanoclusters and carbon-nitrogen materials with Ni single atoms embedded in the crystal lattice. ac -Ni sa / NC catalyst, Ru nanoclusters and Ni single atoms form an interface of tightly coupled single-atom clusters through electron transfer and orbital hybridization; The Ru ac -Ni sa In the / NC catalyst, Ni and Ru respond asymmetrically to light irradiation. Under light irradiation, electrons migrate from Ni to Ru, resulting in electron-rich sites and electron-deficient sites forming on Ru and Ni sites, respectively.

2. The asymmetric photoresponsive electronic pump hydrogen production catalyst according to claim 1, characterized in that, The distance between Ru nanoclusters and Ni single atoms is 0.45 ~ 0.46 nm; the carbon-nitrogen material has a hexagonal structure, with Ru loaded on NC in the form of nanoclusters and forming Ru-N and Ru-Ru bonds; while Ni is anchored on NC in the form of single atoms to form Ni-N bonds.

3. A method for preparing an asymmetric photoresponsive electronic pump hydrogen production catalyst, characterized in that, Includes the following steps: Step 1: Prepare carbonitridium materials for later use; Step 2: Dissolve the carbon-nitrogen material prepared in Step 1 in ethanol, and disperse it thoroughly by ultrasound to obtain a black solution; Step 3: Under heating and stirring conditions, Ni(NO3)2 ethanol solution and RuCl3 ethanol solution are added sequentially to the black solution obtained in Step 2. After continuous stirring, the solution is cooled to room temperature, centrifuged, washed, and dried to obtain a black powder. Step 4: Heat-treat the black powder obtained in step 3 in an inert atmosphere to obtain Ru as described in any one of claims 1 or 2. ac -Ni sa / NC catalyst.

4. The method for preparing an asymmetric photoresponsive electronic pump hydrogen production catalyst according to claim 3, characterized in that, In step 1, the preparation method of the carbon-nitrogen material is as follows: Step 1.1: Add zinc nitrate methanol solution dropwise to 2-methylimidazolium methanol solution to obtain a mixed solution; Step 1.2: After stirring the mixed solution at room temperature, the resulting product is centrifuged, washed, and dried to obtain ZIF-8 powder; Step 1.3: Calcine ZIF-8 powder in an inert atmosphere to obtain carbonitridium material.

5. The method for preparing an asymmetric photoresponsive electronic pump hydrogen production catalyst according to claim 4, characterized in that, In step 1.1, the zinc nitrate methanol solution is prepared by dissolving Zn(NO3)2·6H2O in methanol, and the concentration of zinc nitrate in the zinc nitrate methanol solution is 0.05 mol / L to 0.2 mol / L; the 2-methylimidazole methanol solution is prepared by dissolving 2-methylimidazole in methanol, and the concentration of 2-methylimidazole in the zinc nitrate methanol solution is 0.6 mol / L to 0.8 mol / L.

6. The method for preparing an asymmetric photoresponsive electronic pump hydrogen production catalyst according to claim 4, characterized in that, In step 1.3, the inert atmosphere is argon, and the calcination conditions are: heating to 980~1050℃ at a heating rate of 10℃ / min, and calcination time is 2 hours.

7. The method for preparing an asymmetric photoresponsive electronic pump hydrogen production catalyst according to claim 3, characterized in that, In step 2, the concentration of carbon and nitrogen materials in the black solution is 1~3 g / L.

8. The method for preparing an asymmetric photoresponsive electronic pump hydrogen production catalyst according to claim 3, characterized in that, In step 3, the heating temperature is 80℃; The volume ratio of Ni(NO3)2 ethanol solution to RuCl3 ethanol solution is 1:2, and the concentration of Ni(NO3)2·6H2O in the Ni(NO3)2 ethanol solution is 0.01 g / mL. -1 The concentration of RuCl3·3H2O in the RuCl3 ethanol solution is 0.01 g / mL. -1 .

9. The method for preparing an asymmetric photoresponsive electronic pump hydrogen production catalyst according to claim 3, characterized in that, In step 4, the inert atmosphere is argon, and the heat treatment conditions are: heating to 800 ℃ at a heating rate of 2 ℃ / min, and holding for 2 hours.

10. The application of an asymmetric photoresponsive electronic pump hydrogen production catalyst in dry methane reforming, characterized in that, The catalyst used is prepared by the method for preparing an asymmetric photoresponsive electronic pump hydrogen production catalyst according to any one of claims 3 to 9.

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