Biomass-based hydrogen evolution catalyst and preparation method thereof

Abstract

The invention discloses a biomass-based hydrogen evolution catalyst and a preparation method thereof.The preparation method comprises the following steps that a biomass material is washed clean and dried, then argon is introduced for calcination, the biomass material is ground into powder, and a biomass carbon material is obtained; grinding the biomass carbon material, zinc chloride and ferric trichloride hexahydrate into a molten state, calcining, grinding into powder, adding nitric acid, stirring, carrying out suction filtration, washing to be neutral, and drying to obtain a biomass carbon-Fe material; the biomass carbon-Fe material and ruthenium trichloride are fully ground together, and after argon is introduced for calcination, biomass carbon-RuFe is obtained. The calcining method adopted by the invention is mature in process and high in adaptability, and has the remarkable advantages of continuous and large-scale production; the HER catalytic performance of the prepared material reaches the industrial application standard, a new synthesis template and a new technical normal form are provided for design and development of a hydrogen evolution catalyst, and the method has important guiding significance in promoting biomass energy utilization and upgrading of a hydrogen energy industry technology.

Description

Technical Field

[0001] This invention pertains to catalysts and their preparation methods, specifically a biomass-based hydrogen evolution catalyst and its preparation method. Background Technology

[0002] Hydrogen energy, as a clean and efficient secondary energy source, is a key vehicle for promoting energy structure transformation and achieving the goals of "carbon peaking and carbon neutrality." Electrocatalytic water splitting for hydrogen production is one of the most promising green hydrogen production technologies, with the hydrogen evolution reaction (HER) at the cathode being the efficiency bottleneck of the entire process. Therefore, developing efficient, stable, and low-cost HER catalysts is of great significance for reducing the energy consumption and cost of water electrolysis for hydrogen production and promoting the large-scale application of hydrogen energy.

[0003] Currently, platinum (Pt)-based noble metal catalysts remain the best-performing HER catalysts, but their high cost and scarcity severely limit their large-scale commercial application. To reduce dependence on Pt, researchers are focusing on two alternatives: one is developing non-noble metal catalysts (such as transition metal phosphides and sulfides), but their activity and stability are generally difficult to match Pt; the other is developing low- or ultra-low-platinum supported catalysts, as well as other noble metal catalysts with activity close to Pt but relatively inexpensive. Among these, ruthenium (Ru) is considered a highly promising Pt substitute due to its moderate hydrogen bonding strength and price, which is only about one-third that of Pt.

[0004] However, pure Ru nanoparticles are prone to aggregation, leading to a reduction in active sites and decreased stability. To address this issue, they typically need to be loaded onto conductive substrates with high specific surface area, such as commercial carbon black, carbon nanotubes, and graphene. While these traditional carbon materials exhibit good conductivity, their preparation processes are often energy-intensive, involve toxic chemicals, and are expensive, which contradicts the initial goal of developing green and low-cost hydrogen production technologies. More importantly, the interaction between these inert substrates and Ru nanoparticles is usually weak, making it impossible to effectively modulate the electronic structure of Ru to further enhance its intrinsic activity.

[0005] Zhang Qian et al. prepared cellulose nanofibers from wood pulp via oxidation with 2,2,6,6-tetramethylpiperidine oxide (TEMPO). Using urea as a nitrogen source and glucose as a carbon source, they successfully synthesized Ru / NC materials with excellent hydrogen evolution properties after ruthenium trichloride compounding, freeze-drying, and high-temperature calcination. However, this synthetic route has the following limitations: the preparation of cellulose nanofibers relies on the expensive TEMPO oxidant, and subsequent effective dispersion of the material requires specialized physical aqueous phase reverse collision equipment, resulting in high overall process costs and complexity, making it difficult to meet the requirements of industrial production. Summary of the Invention

[0006] Purpose of the invention: In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a low-cost method for preparing a biomass-based hydrogen evolution catalyst. Another purpose of this invention is to provide a biomass-based catalyst with excellent hydrogen evolution performance.

[0007] Technical solution: The preparation method of a biomass-based hydrogen evolution catalyst according to the present invention includes the following steps:

[0008] Step 1: Rinse the biomass material clean, dry it, calcine it with argon gas, and grind it into powder to obtain biomass carbon material;

[0009] Step 2: Grind the biomass carbon material together with zinc chloride and ferric chloride hexahydrate until it is molten, calcine it, grind it into powder, add nitric acid and stir, filter and wash until neutral, and dry to obtain biomass carbon-Fe material;

[0010] Step 3: Grind the biomass carbon-Fe material together with ruthenium trichloride, and calcine it with argon gas to obtain a biomass-based hydrogen evolution catalyst, namely biomass carbon-RuFe nanoparticles.

[0011] Furthermore, in step one, the biomass material can be any one of bamboo leaves, reed stalks, rice husks, or horsetail. As a carbon substrate, biomass materials not only enable the green and low-cost preparation of catalysts from the source, but their unique microstructure and surface chemical properties also promise to interact strongly with Ru nanoparticles, optimizing the electronic state of Ru and thus synergistically enhancing the HER catalytic performance.

[0012] Furthermore, in step one, the calcination temperature is 200~300℃, and the heating rate is 3~5℃ / min.

[0013] Furthermore, in step two, the mass ratio of biomass carbon material, zinc chloride, and ferric chloride hexahydrate is 1:1:3~5.

[0014] Furthermore, in step two, the calcination temperature is 700~800℃, and the heating rate is 3~5℃ / min.

[0015] Furthermore, in step two, the volume percentage of nitric acid is 5-10 vol.

[0016] Furthermore, in step three, the mass ratio of biomass carbon-Fe material to ruthenium trichloride is 5:3~5.

[0017] Furthermore, in step three, the calcination temperature is 350~450℃, and the heating rate is 1~2℃ / min.

[0018] Furthermore, in step three, the calcined material is kept at a constant temperature for 1-2 hours.

[0019] The biomass-based hydrogen evolution catalyst prepared by the above method consists of RuFe nanoparticles supported on a carbon substrate to achieve efficient HER conversion. Alloying Ru with Fe can further optimize the d-band centers of Ru, reducing its adsorption energy for reaction intermediates, theoretically yielding superior catalytic activity compared to single-metal Ru. In alkaline media, the overpotential of this type of hydrogen evolution catalyst is generally lower than that of commercial Pt / C, with the HER electrode overpotential as low as 20.2 mV.

[0020] Preparation principle: Biomass-based hydrogen evolution catalysts can utilize biomass-derived, structurally tunable doped carbon materials as high-performance supports. Through their unique pore structure, electronic structure, and surface chemistry, they work synergistically with the supported metal / active components to reduce the energy barrier of the hydrogen evolution reaction, achieving efficient, stable, and low-cost hydrogen production.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0022] 1. The biomass materials used are waste biomass materials, which have the significant advantage of low cost. By converting them into high-value-added catalysts, the environmental challenges brought by waste biomass materials can be transformed into a new engine to promote green technology revolution and economic growth.

[0023] 2. The calcination process used is mature and highly adaptable, and has significant advantages in continuous and large-scale production;

[0024] 3. The HER catalytic performance of the prepared materials all meet the standards for industrial application, thus providing a new synthetic template and technical paradigm for the design and development of hydrogen evolution catalysts, which has important guiding significance for promoting the utilization of biomass energy and the technological upgrading of the hydrogen energy industry;

[0025] 4. This invention provides a universal preparation strategy applicable to various waste biomass, and successfully constructs a series of hydrogen evolution catalytic supports. The core advantage of this invention lies in the diversity and tunability of raw materials. By flexibly selecting different biomass carbon-Fe materials, it is possible to achieve directional control of key characteristics such as support pore size and surface chemistry, thereby optimizing its catalytic performance. Attached Figure Description

[0026] Figure 1 The images shown are HRTEM images of the bamboo leaf carbon-Fe material in this invention, where a is the HRTEM image at a scale bar of 100 nm and b is the HRTEM image at a scale bar of 20 nm.

[0027] Figure 2The images are HRTEM images of the *Equisetum hyemale* carbon-Fe material in this invention, where a is the HRTEM image at a scale bar of 200 nm and b is the HRTEM image at a scale bar of 20 nm.

[0028] Figure 3 The images shown are HRTEM images of the rice husk carbon-Fe material in this invention, where a is the HRTEM image at a scale bar of 50 nm and b is the HRTEM image at a scale bar of 20 nm.

[0029] Figure 4 The images shown are HRTEM images of the reed stalk carbon-Fe material in this invention, where a is the HRTEM image at a scale bar of 200 nm and b is the HRTEM image at a scale bar of 20 nm.

[0030] Figure 5 The images shown are HRTEM images of bamboo leaf carbon-RuFe nanoparticles in this invention, where a is an HRTEM image with a scale bar of 50 nm, b is an HRTEM image with a scale bar of 20 nm, and c is an HRTEM image with a scale bar of 5 nm.

[0031] Figure 6 The images shown are HRTEM images of the Equisetum hyemale carbon-RuFe nanoparticles in this invention, where a is the HRTEM image at a scale bar of 50 nm, b is the HRTEM image at a scale bar of 20 nm, and c is the HRTEM image at a scale bar of 5 nm.

[0032] Figure 7 The images shown are HRTEM images of rice husk carbon-RuFe nanoparticles in this invention, where a is an HRTEM image with a scale bar of 50 nm, b is an HRTEM image with a scale bar of 20 nm, and c is an HRTEM image with a scale bar of 5 nm.

[0033] Figure 8 The images shown are HRTEM images of carbon-RuFe nanoparticles from reed stalks in this invention, where a is an HRTEM image with a scale bar of 50 nm, b is an HRTEM image with a scale bar of 20 nm, and c is an HRTEM image with a scale bar of 5 nm.

[0034] Figure 9The images show a comparison of the Fe 2p values ​​of the following materials in this invention: bamboo leaf carbon-Fe material, bamboo leaf carbon-RuFe nanoparticles, horsetail carbon-Fe material, horsetail carbon-RuFe nanoparticles, rice husk carbon-Fe material, rice husk carbon-RuFe nanoparticles, reed stalk carbon-Fe material, and reed stalk carbon-RuFe nanoparticles. Specifically, image a shows a comparison of the Fe 2p values ​​of the following materials: image a is a comparison of the Fe 2p values ​​of the following materials: image a is a comparison of the Fe 2p values ​​of the following materials: image b is a comparison of the Fe 2p values ​​of the following materials: image a ...

[0035] Figure 10 These are comparison images of the O 1s values ​​of bamboo leaf carbon-Fe materials, bamboo leaf carbon-RuFe nanoparticles, horsetail carbon-Fe materials, horsetail carbon-RuFe nanoparticles, rice husk carbon-Fe materials, rice husk carbon-RuFe nanoparticles, reed stalk carbon-Fe materials, and reed stalk carbon-RuFe nanoparticles in this invention. Image a shows the O 1s values ​​of the bamboo leaf carbon-Fe materials, bamboo leaf carbon-RuFe nanoparticles, horsetail carbon-Fe materials, and horsetail carbon-RuFe nanoparticles, while image b shows the O 1s values ​​of the rice husk carbon-Fe materials, rice husk carbon-RuFe nanoparticles, reed stalk carbon-Fe materials, and reed stalk carbon-RuFe nanoparticles.

[0036] Figure 11 The images show a comparison of Ru 3p values ​​for bamboo leaf carbon-RuFe nanoparticles, horsetail carbon-RuFe nanoparticles, rice husk carbon-RuFe nanoparticles, and reed stalk carbon-RuFe nanoparticles in this invention. In particular, a is a comparison of Ru 3p values ​​for bamboo leaf carbon-RuFe nanoparticles and horsetail carbon-RuFe nanoparticles, and b is a comparison of Ru 3p values ​​for rice husk carbon-RuFe nanoparticles and reed stalk carbon-RuFe nanoparticles.

[0037] Figure 12 ICP comparison images of bamboo leaf carbon-Fe material, bamboo leaf carbon-RuFe nanoparticles, horsetail carbon-Fe material, horsetail carbon-RuFe nanoparticles, rice husk carbon-Fe material, rice husk carbon-RuFe nanoparticles, reed stalk carbon-Fe material, and reed stalk carbon-RuFe nanoparticles in this invention.

[0038] Figure 13 The HER performance test diagrams of bamboo leaf carbon-RuFe nanoparticles, horsetail carbon-RuFe nanoparticles, rice husk carbon-RuFe nanoparticles, and reed stalk carbon-RuFe nanoparticles in this invention are shown.

[0039] Figure 14 The HER performance test chart is for comparison. Detailed Implementation

[0040] Unless otherwise specified, all materials and reagents used in the following embodiments are commercially available. Experimental methods not specifically described in the embodiments are generally performed under standard conditions or as recommended by the manufacturer.

[0041] Example 1

[0042] A method for preparing a biomass-based hydrogen evolution catalyst includes the following steps:

[0043] (1) Spread the bamboo leaves evenly on the tin foil, rinse them with distilled water, and dry them in a 60℃ oven. Place the dried bamboo leaves in a magnetic boat and place them in a tube furnace for calcination. Pour argon gas through the furnace, raise the temperature at a rate of 5℃ / min, and calcinate at 300℃ for 1 hour. Remove the bamboo leaves, grind them into powder, and obtain bamboo leaf carbon material.

[0044] (2) Take 0.3000g of bamboo leaf carbon material, 0.3000g of zinc chloride powder, and 0.9000g of ferric chloride hexahydrate and grind them into a magnetic boat until they are molten. Place the magnetic boat in a tube furnace for calcination, purge with nitrogen, raise the temperature at a rate of 5℃ / min, and calcinate at 800℃ for 2 hours. Take out the calcined material and grind it into powder. Add 10 vol% nitric acid and stir for 2 minutes. Filter and wash the bamboo leaf material with double-distilled water until neutral. Place it in a vacuum oven and dry for 2 days to obtain bamboo leaf carbon-Fe material.

[0045] (3) Take 0.0250g of bamboo leaf carbon-Fe material and add 0.0150g of ruthenium trichloride into a magnetic boat, grind it thoroughly for 20 minutes, place it in a tube furnace for calcination, pass argon gas, raise the temperature at a rate of 2℃ / min, calcination temperature is 450℃, keep warm for 1h, take it out and collect it to obtain bamboo leaf carbon-RuFe nanoparticles.

[0046] The materials obtained in this embodiment include: Fe: 32.32 wt%, Ru: 4.94 wt%.

[0047] Example 2

[0048] A method for preparing a biomass-based hydrogen evolution catalyst includes the following steps:

[0049] (1) Spread the horsetail grass evenly on tin foil, rinse it with distilled water, and put it into a 60℃ oven to dry the moisture. Put the dried horsetail grass into a magnetic boat and place it in a tube furnace for calcination. Argon gas is introduced, the heating rate is 5℃ / min, the calcination temperature is 300℃, and the temperature is maintained for 1 hour. After that, it is taken out and ground into powder to obtain horsetail grass carbon material.

[0050] (2) Take 0.3000g of horsetail carbon material, 0.3000g of zinc chloride powder, and 0.9000g of ferric chloride hexahydrate and grind them in a magnetic boat until they are molten. Place the magnetic boat in a tube furnace for calcination, purge with nitrogen, raise the temperature at a rate of 5℃ / min, and calcinate at 800℃ for 2 hours. Take out the calcined material and grind it into powder. Add 10 vol% nitric acid and stir for 2 minutes. Filter and wash the horsetail material with double-distilled water until neutral. Place it in a vacuum oven and dry for 2 days to obtain horsetail carbon-Fe material.

[0051] (3) Take 0.0250g of horsetail carbon-Fe material and add 0.0150g of ruthenium trichloride into a magnetic boat, grind it thoroughly for 20 minutes, place it in a tube furnace for calcination, pass argon gas, raise the temperature at a rate of 2℃ / min, calcination temperature is 450℃, keep warm for 1h, take it out and collect it to obtain horsetail carbon-RuFe nanoparticles.

[0052] The material obtained in this embodiment includes: Fe: 28.43 wt%, Ru: 7.93 wt%.

[0053] Example 3

[0054] A method for preparing a biomass-based hydrogen evolution catalyst includes the following steps:

[0055] (1) Spread the rice husks evenly on tin foil, rinse them with distilled water, and dry them in a 60°C oven. Place the dried rice husks in a magnetic boat and calcine them in a tube furnace. Pour argon gas through the furnace, raise the temperature at a rate of 5°C / min, and calcine at 300°C for 1 hour. Remove the calcined rice husks and grind them into powder to obtain rice husk carbon material.

[0056] (2) Take 0.3000g of rice husk carbon material, 0.3000g of zinc chloride powder, and 0.9000g of ferric chloride hexahydrate and grind them into a magnetic boat until they are molten. Place the magnetic boat in a tube furnace for calcination, purge with nitrogen, raise the temperature at a rate of 5℃ / min, and calcinate at 800℃ for 2 hours. Take out the calcined material and grind it into powder. Add 10 vol% nitric acid and stir for 2 minutes. Filter and wash the rice husk material with double-distilled water until neutral. Place it in a vacuum oven and dry for 2 days to obtain rice husk carbon-Fe material.

[0057] (3) Take 0.0250g of rice husk carbon-Fe material and add 0.0150g of ruthenium trichloride into a magnetic boat, grind it thoroughly for 20 minutes, place it in a tube furnace for calcination, pass argon gas, raise the temperature at a rate of 2℃ / min, calcination temperature is 450℃, keep warm for 1h, take it out and collect it to obtain rice husk carbon-RuFe nanoparticles.

[0058] The materials obtained in this embodiment include: Fe: 0.47 wt%, Ru: 8.03 wt%.

[0059] Example 4

[0060] A method for preparing a biomass-based hydrogen evolution catalyst includes the following steps:

[0061] (1) Spread the reeds evenly on tin foil, rinse them with distilled water, and dry them in a 60°C oven. Place the dried reeds in a magnetic boat and calcine them in a tube furnace. Pour argon gas through the furnace, raise the temperature at a rate of 5°C / min, and calcine at 300°C for 1 hour. Remove the reeds, grind them into powder, and obtain the reed carbon material.

[0062] (2) Take 0.3000g of reed stalk carbon material, 0.3000g of zinc chloride powder, and 0.9000g of ferric chloride hexahydrate and grind them in a magnetic boat until they are molten. Place the magnetic boat in a tube furnace for calcination, purge with nitrogen, raise the temperature at a rate of 5℃ / min, and calcinate at 800℃ for 2 hours. Take out the calcined material and grind it into powder. Add 10 vol% nitric acid and stir for 2 minutes. Filter and wash the reed stalk material with double-distilled water until neutral. Place it in a vacuum oven and dry for 2 days to obtain reed stalk carbon-Fe material.

[0063] (3) Take 0.0250g of reed stalk carbon-Fe material and add 0.0150g of ruthenium trichloride into a magnetic boat, grind it thoroughly for 20 minutes, place it in a tube furnace for calcination, pass argon gas, raise the temperature at a rate of 2℃ / min, calcination temperature is 450℃, keep warm for 1h, take it out and collect it to obtain reed stalk carbon-RuFe nanoparticles.

[0064] The material obtained in this embodiment includes: Fe: 2.14 wt%, Ru: 11.77 wt%.

[0065] Example 5

[0066] A method for preparing a biomass-based hydrogen evolution catalyst includes the following steps:

[0067] (1) Spread the bamboo leaves evenly on the tin foil, rinse them with distilled water, and dry them in a 60℃ oven. Place the dried bamboo leaves in a magnetic boat and place them in a tube furnace for calcination. Pour argon gas through the furnace, raise the temperature at a rate of 3℃ / min, and calcinate at 250℃ for 1 hour. Remove the bamboo leaves, grind them into powder, and obtain bamboo leaf carbon material.

[0068] (2) Take 0.3000g of bamboo leaf carbon material, 0.3000g of zinc chloride powder, and 1.5000g of ferric chloride hexahydrate and grind them into a magnetic boat until they are molten. Place the magnetic boat in a tube furnace for calcination, purge with nitrogen, raise the temperature at a rate of 3℃ / min, and calcinate at 700℃ for 2 hours. Take out the calcined material and grind it into powder. Add 5 vol% nitric acid and stir for 2 minutes. Filter and wash the bamboo leaf material with double-distilled water until neutral. Place it in a vacuum oven and dry for 2 days to obtain bamboo leaf carbon-Fe material.

[0069] (3) Take 0.0250g of bamboo leaf carbon-Fe material and add 0.0250g of ruthenium trichloride into a magnetic boat, grind it thoroughly for 20 minutes, place it in a tube furnace for calcination, pass argon gas, raise the temperature at a rate of 1℃ / min, calcination temperature is 450℃, keep warm for 1h, take it out and collect it to obtain bamboo leaf carbon-RuFe nanoparticles.

[0070] Example 6

[0071] A method for preparing a biomass-based hydrogen evolution catalyst includes the following steps:

[0072] (1) Spread the bamboo leaves evenly on the tin foil, rinse them with distilled water, and dry them in a 60℃ oven. Place the dried bamboo leaves in a magnetic boat and place them in a tube furnace for calcination. Pour argon gas through the furnace, raise the temperature at a rate of 4℃ / min, and calcinate at 280℃ for 1 hour. Remove the bamboo leaves, grind them into powder, and obtain bamboo leaf carbon material.

[0073] (2) Take 0.3000g of bamboo leaf carbon material, 0.3000g of zinc chloride powder, and 1.2000g of ferric chloride hexahydrate and grind them into a magnetic boat until they are molten. Place the magnetic boat in a tube furnace for calcination, purge with nitrogen, raise the temperature at a rate of 4℃ / min, and calcinate at 780℃ for 2 hours. Take out the calcined material and grind it into powder. Add 8 vol% nitric acid and stir for 2 minutes. Filter and wash the bamboo leaf material with double-distilled water until neutral. Place it in a vacuum oven and dry for 2 days to obtain bamboo leaf carbon-Fe material.

[0074] (3) Take 0.0250g of bamboo leaf carbon-Fe material and add 0.0200g of ruthenium trichloride into a magnetic boat, grind it thoroughly for 20 minutes, place it in a tube furnace for calcination, pass argon gas, heat up at a rate of 1.5℃ / min, calcination temperature is 420℃, keep warm for 1.5h, take it out and collect it to obtain bamboo leaf carbon-RuFe nanoparticles.

[0075] Figures 1-4HRTEM images of biomass carbon-Fe materials prepared from biomass materials show that all four types of biomass carbon-Fe materials formed a lamellar structure with obvious wrinkles. This structure, as a carrier, possesses a large specific surface area and good electrical conductivity, which not only effectively inhibits the aggregation of Ru nanoparticles during the loading process but also creates favorable conditions for electron transfer in electrocatalytic reactions.

[0076] Figures 5-8 The images show HRTEM images of RuFe nanoparticles on different biomass carbon substrates. As can be seen, the RuFe nanoparticles exist in a clear nanoparticle morphology and exhibit a highly uniform monodisperse state across the entire support surface. This uniformly dispersed particle morphology facilitates the exposure of more active sites and provides an ideal structural basis for electron and mass transport in catalytic reactions.

[0077] Figure 9 The Fe2p XPS peak fitting results of different biomass carbon-loaded Fe materials and RuFe nanoparticles formed after further Ru loading are presented. Analysis revealed that after Ru loading, the Fe2p peaks of the four biomass carbon-Fe materials... 2+ 2p 3 / 2 The binding energy did not change significantly, while the Fe in the rice husk-based material... 2+ 2p 1 / 2 The binding energy increased by 0.68 eV. In comparison, Fe... 3+ The 2P orbitals generally exhibit significant shifts after Ru loading: Fe in bamboo leaf carbon-Fe materials and rice husk carbon-Fe materials 3+ 2p 1 / 2 The binding energies increased by 0.54 eV and 1.22 eV, respectively, indicating that the introduction of Ru enhanced the metal-support interaction, which is beneficial for stabilizing active centers and may induce the formation of new active sites on the support surface, thereby achieving synergistic catalytic effects of multiple active centers. On the other hand, after loading Ru onto the *Equisetum hyemale* carbon-Fe materials and *Phragmites australis* carbon-Fe materials, the Fe... 3+ 2p 1 / 2 The binding energy decreased by 0.41 eV. This negative shift indicates that the electron density of the active site increased, which helps to optimize the adsorption behavior of hydrogen intermediates, reduce the overpotential of hydrogen evolution reaction, and thus improve the electrocatalytic hydrogen evolution performance.

[0078] Figure 10 XPS spectra of Ru in the 3p energy region for different biomass carbon-RuFe nanoparticles. The figure mainly shows two sets of peaks, corresponding to Ru respectively. 0 (461.9 eV and 484.2 eV) and Ru 4+ (463.2 eV and 485.5 eV), indicating that Ru exists in both metallic and oxidized states.

[0079] The Fe 2p and Ru 3p energy level spectra further revealed the electronic structure characteristics inside the RuFe nanoparticles, providing crucial information for a deeper understanding of the electronic states and energy level distribution of the material. Electronic structure optimization can effectively promote the improvement of electron mobility, thereby significantly enhancing catalytic activity.

[0080] Figure 11 For the O1s peak fitting spectra of different biomass carbon-Fe materials and RuFe nanoparticles, from Figure 11 As can be seen, compared with biomass carbon-Fe materials, the metal-oxygen bonds of biomass carbon-RuFe nanoparticles have shifted to varying degrees, with the corresponding peaks shifting in the positive direction in the range of 0.48-0.82 eV. This may be due to the relatively high electronegativity of Ru, which attracts electrons from Fe atoms, leading to an increase in the effective oxidation state of Fe.

[0081] Figure 12 The metal content (expressed as wt%) of four biomass-derived carbon-Fe materials and their RuFe content was determined by inductively coupled plasma (ICP) analysis. Figure 12 As can be seen, among different biomass carbon-Fe materials, the mass percentage of Fe is highest in the horsetail carbon-Fe material and lowest in the reed stalk carbon-Fe material. In terms of biomass carbon-RuFe nanoparticles, the Fe content is highest in the bamboo leaf carbon-RuFe nanoparticles and lowest in the rice husk carbon-RuFe nanoparticles. In terms of Ru content, the Ru content is highest in the reed stalk carbon-RuFe material and lowest in the bamboo leaf carbon-RuFe material.

[0082] Figure 13 The HER performance test chart for the material is shown below. Figure 13 The results show that the four different biomass carbon-RuFe nanoparticles screened out were subjected to a current density of 10 mA cm⁻¹. -2 The overpotential ranged from 20.2 to 27.3 mV, which was significantly lower than that of commercial Pt / C, demonstrating excellent catalytic activity in the hydrogen evolution reaction.

[0083] Figure 14 To compare the HER performance test charts, from Figure 14 As can be seen from the data, by using other biomass materials as carbon carriers, changing the experimental procedure, calcination temperature, and metal type, RuFe nanoparticles were prepared under conditions such as a current density of 10 mA cm⁻¹. -2 The overpotential ranged from 40.9 to 123.0 mV, which was significantly lower than that of commercial Pt / C. This means that changing the existing production process will lead to a significant reduction in hydrogen evolution catalytic activity.

[0084] Comparative Example 1

[0085] The remaining steps of this comparative example are the same as those of Example 1, except that the bamboo leaves in the biomass material are replaced with corn stalks.

[0086] Comparative Example 2

[0087] The remaining steps of this comparative example are the same as those in Example 1, except that the nitric acid washing is omitted, while the other operations are the same.

[0088] Comparative Example 3

[0089] The remaining steps of this comparative example are the same as those of Example 1, except that the calcination temperature in step (3) is replaced with 300°C.

[0090] Comparative Example 4

[0091] The remaining steps of this comparative example are the same as those of Example 1, except that ferric chloride hexahydrate in step (3) is replaced with nickel chloride hexahydrate.

[0092] The catalysts obtained in Examples 1-4 and Comparative Examples 1-4 were used for the HER catalytic reaction. Specifically, 1 mg of the prepared sample was weighed, and 10 μL of 1% naphthol, 50 μL of ethanol, and 140 μL of distilled water were added. The mixture was ultrasonically dispersed for 20 minutes. 4 μL of the sample was then dropped onto a glassy carbon electrode and incubated at 40 °C. o The sample was dried in an oven at C, and then 2 μL of the sample was dropped onto the glassy carbon electrode. After drying, 2 μL of 0.1% naphthol was used to seal the sample to obtain the working electrode. The carbon rod was used as the counter electrode and the mercury oxide electrode was used as the reference electrode to test the hydrogen evolution performance.

[0093] The results showed that replacing biomass materials, changing experimental procedures, altering calcination temperature, and selecting different metals all significantly impacted catalytic performance. For example, in Comparative Example 1, replacing bamboo leaves in the biomass material with other biomass materials, such as corn husks, resulted in changes in catalytic performance at 10 mA / cm². -2 The overpotential increased to 123.0 mV; in Comparative Example 2, the nitric acid washing step was omitted, and the material was at 10 mAcm⁻¹ -2 The overpotential increased to 69.4 mV; in Comparative Example 3, the calcination temperature was reduced to 300°C. o C, the material is at 10 mAcm -2 The overpotential increased to 49.0 mV; in Comparative Example 4, ferric chloride hexahydrate was replaced with nickel chloride hexahydrate, and the material was at 10 mAcm⁻¹ -2 The overpotential increased to 40.9 mV.

Claims

1. A method for preparing a biomass-based hydrogen evolution catalyst, characterized in that, Includes the following steps: Step 1: Rinse the biomass material clean, dry it, calcine it with argon gas, and grind it into powder to obtain biomass carbon material; Step 2: Grind the biomass carbon material together with zinc chloride and ferric chloride hexahydrate until it is molten, calcine it, grind it into powder, add nitric acid and stir, filter and wash until neutral, and dry to obtain biomass carbon-Fe material; Step 3: Grind the biomass carbon-Fe material together with ruthenium trichloride, and calcine it with argon gas to obtain a biomass-based hydrogen evolution catalyst.

2. The method for preparing a biomass-based hydrogen evolution catalyst according to claim 1, characterized in that: In step one, the biomass material is any one of bamboo leaves, reed stalks, rice husks, or horsetail.

3. The method for preparing a biomass-based hydrogen evolution catalyst according to claim 1, characterized in that: In step one, the calcination temperature is 200~300℃, and the heating rate is 3~5℃ / min.

4. The method for preparing a biomass-based hydrogen evolution catalyst according to claim 1, characterized in that: In step two, the mass ratio of biomass carbon material, zinc chloride, and ferric chloride hexahydrate is 1:1:3~5.

5. The method for preparing a biomass-based hydrogen evolution catalyst according to claim 1, characterized in that: In step two, the calcination temperature is 700~800℃, and the heating rate is 3~5℃ / min.

6. The method for preparing a biomass-based hydrogen evolution catalyst according to claim 1, characterized in that: In step two, the volume percentage of nitric acid is 5-10 vol%.

7. The method for preparing a biomass-based hydrogen evolution catalyst according to claim 1, characterized in that: In step three, the mass ratio of biomass carbon-Fe material to ruthenium trichloride is 5:3~5.

8. The method for preparing a biomass-based hydrogen evolution catalyst according to claim 1, characterized in that: In step three, the calcination temperature is 350~450℃, and the heating rate is 1~2℃ / min.

9. The method for preparing a biomass-based hydrogen evolution catalyst according to claim 1, characterized in that: In step three, the calcined material is kept at a constant temperature for 1-2 hours.

10. A biomass-based hydrogen evolution catalyst obtained by the preparation method of the biomass-based hydrogen evolution catalyst according to any one of claims 1 to 9, characterized in that: RuFe nanoparticles are supported on a carbon substrate.

Images