A wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen generation catalyst

Abstract

The application discloses a kind of wood-derived carbon supported metal oxide-alloy heterojunction hydrogen production catalyst, wood-derived carbon supported metal oxide-alloy heterojunction hydrogen production catalyst has metal oxide-alloy heterojunction formation, and is loaded on wood-derived carbon base;The catalyst comprises catalytically active metal element and non-metal element.The preparation process of the present application is simple, the use of metal is transition metal, and the cost is low.The prepared nickel iron molybdenum heterojunction water electrolysis hydrogen production catalyst has;Ni3Fe / MoO2 heterojunction is loaded on wood-derived carbon base, and has good hydrogen evolution reaction (HER) electrochemical catalytic activity in alkaline solution, reaches-10mA / cm 2 Required overpotential is less than or equal to 150mV, and hydrogen evolution reaction (OER) reaches 300mA / cm 2 Required overpotential is less than or equal to 500mV, which lays a technical foundation for reducing the cost of industrial water electrolysis hydrogen production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen catalysts for electrolysis of water, in particular to a wood-derived carbon supported metal oxide-alloy heterojunction hydrogen catalyst. BACKGROUND

[0002] Hydrogen energy is a renewable clean energy with broad development prospects, which is conducive to solving the growing global energy demand. Water electrolysis as an ideal method of hydrogen production has attracted widespread attention in recent years. In practical situations, the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode in the water electrolysis process have high overpotential, which limits the further application of water electrolysis for hydrogen production, resulting in slow kinetics. Therefore, it is necessary to develop efficient water electrolysis catalysts to accelerate the reaction process. Noble metals (Pt, Ru) can effectively accelerate the process of water electrolysis for hydrogen production, but due to their high price and low reserves, their industrial application is limited. Transition metals (Ni, Mo, Fe, etc.) have the advantages of low price and large reserves, and have certain performance in water electrolysis for hydrogen production, and have great development prospects.

[0003] In addition, the commonly used substrates in electrodes are mainly concentrated in metal foams or carbon cloth, and their complex preparation process and high cost restrict the application of electrodes. As the most abundant biopolymer on earth, wood has a unique three-dimensional porous structure, a variety of functional groups capable of coordinating with metal ions, and excellent conductivity and high rate performance after high-temperature annealing, as well as ultra-high porosity and specific surface area. The combination of catalytic metal species and high-conductivity carbon matrix can effectively prevent metal nanoparticle agglomeration, avoid corrosion by strong acid and strong base, and at the same time improve the activity and stability of metal catalysts.

[0004] Therefore, developing a low-cost and efficient transition metal-based wood-derived carbon electrode is the key to solving the above problems. SUMMARY

[0005] To solve the above technical problems, the present application provides a wood-derived carbon supported metal oxide-alloy heterojunction hydrogen catalyst, which aims to obtain a metal oxide-alloy heterojunction water electrolysis hydrogen catalyst loaded on a wood-derived carbon substrate with simple process, low cost and good catalytic performance.

[0006] To achieve the above purpose, the technical solutions provided by the present application are as follows:

[0007] A wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst has a metal oxide-alloy heterojunction formed and supported on a wood-derived carbon substrate; the catalyst contains a catalytically active metal element and a non-metal element, wherein the catalytically active metal element is at least one selected from Ni, Fe, Mo, V, Co, W, and Cr; the non-metal element is C and / or O; wherein the active group is dispersed within the catalyst.

[0008] Furthermore, the XRD pattern of the catalyst shows diffraction peaks belonging to wood-derived carbon, metal alloys, and metal oxides.

[0009] The preparation method of the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst as described above includes the following steps:

[0010] (1) Heat wood chips in distilled water at 80°C for 10 hours. First, add a mixed solution of deionized water, acetic acid and sodium chlorite. After heating for 10 hours, add the wood chips to the mixed solution and stir at 60-70 rpm at 80°C for 1 hour. Second, add the same mass of acetic acid and sodium chlorite as the first time and continue stirring at 60-70 rpm at 80°C. Finally, remove the wood chips and air dry them to obtain pretreated wood chips. The mass ratio of the added wood chips to the first added deionized water, acetic acid and sodium chlorite is 1-5:100-300:1-10:1-10.

[0011] (2) Dissolve metal salt A in a solvent to obtain metal salt A solution, put the pretreated wood chips in step (1) into the obtained metal salt A solution, vacuum impregnate for 8 hours, take out the wood chips after impregnation, clean and dry to obtain impregnated wood chips; the metal salt A is one of iron salt, nickel salt or cobalt salt;

[0012] (3) Place the wood chips obtained after impregnation in step (2) in a tube furnace and calcine them at 800-1200℃ for 1-6 hours to obtain sample B;

[0013] (4) Dissolve metal salt C in a solvent to obtain metal salt C solution. Put the metal salt C solution and the sample B from step (2) into a reaction vessel and stir to carry out a solvothermal reaction. After the reaction is completed, cool to room temperature, take out the material obtained from the reaction vessel, clean and dry to obtain a preliminary sample. The solvothermal reaction is carried out at 100-200℃ for 2-48 hours. The metal salt C is obtained by mixing metal salt D and metal salt E in any proportion. Metal salt D is one or two metal salts different from those in metal salt A solution, such as iron salt, nickel salt, and cobalt salt. Metal salt E is one of molybdenum salt, vanadium salt, chromium salt, and tungsten salt.

[0014] (5) Place the preliminary sample obtained in step (4) in a tube furnace and calcine it at 200-900°C with a mixture of hydrogen and argon for 1-6 hours to obtain a wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst.

[0015] Preferably, the mass ratio of the wood chips added in step (1) to the first added deionized water, acetic acid, and sodium chlorite is 3-4:130-250:1-5:1-4; the wood chips added in step (1) are one of the following natural woods: pine, poplar, balsa wood, birch, fir, beech, or eucalyptus.

[0016] Preferably, the nickel salt mentioned in step (2) is nickel chloride, nickel acetylacetonate, nickel acetate, nickel bromide, nickel iodide, nickel sulfate, nickel nitrate, or nickel ammonium sulfate; the cobalt salt mentioned in step (2) is one of cobalt chloride, cobalt sulfate, cobalt nitrate, cobalt carbonate, cobalt acetate, cobalt oxalate, cobalt phosphate, cobalt bromide, cobalt iodide, or cobalt sulfide; the iron salt mentioned in step (2) is one of ferric chloride, ferric sulfate, ferric nitrate, ferric carbonate, ferric oxalate, ferric phosphate, ferric bromide, ferric iodide, ferrous sulfate, ferric sulfate, ferrous nitrate, or ferrous chloride; and the solvents mentioned in steps (2) and (4) are water, methanol, ethanol, ethylene glycol, isopropanol, n-butanol, n-hexane, cyclohexane, diethyl ether, or petroleum ether.

[0017] Preferably, the concentration of the metal salt A solution in step (2) is 0.001-5 mmol / mL; in step (3), argon gas is introduced at 800-900℃ for high-temperature calcination, and the holding time is 2-6 hours.

[0018] Preferably, in step (4), the stirring speed is 60-70 rpm, the temperature is 80°C, and the stirring time is 15 minutes; the solvothermal reaction is carried out at 120-180°C for 8-20 hours; and the concentrations of metal salt D and metal salt E in step (4) are each 0.001-10 mmol / mL.

[0019] Preferably, the nickel salt mentioned in step (4) is nickel chloride, nickel acetylacetone, nickel acetate, nickel bromide, nickel iodide, nickel sulfate, nickel nitrate, or nickel ammonium sulfate; the cobalt salt mentioned in step (4) is one of cobalt chloride, cobalt sulfate, cobalt nitrate, cobalt carbonate, cobalt acetate, cobalt oxalate, cobalt phosphate, cobalt bromide, cobalt iodide, or cobalt sulfide; the iron salt mentioned in step (4) is one of ferric chloride, ferric sulfate, ferric nitrate, ferric carbonate, ferric oxalate, ferric phosphate, ferric bromide, ferric iodide, ferrous sulfate, ferric sulfate, ferrous nitrate, or ferrous chloride; the molybdenum salt mentioned in step (4) is sodium molybdate, ammonium molybdate, or... One of calcium molybdate, potassium molybdate, ammonium hydrogen molybdate, ammonium phosphomolybdate, and molybdenum pentachloride; one of the vanadium salts mentioned in step (4), namely vanadium sulfate, vanadium chloride, vanadium nitrate, sodium metavanadate, potassium metavanadate, vanadium pentoxide, ammonium vanadate, vanadium trioxide, and vanadium oxysulfate; one of the chromium salts mentioned in step (4), namely chromium nitrate, potassium chromate, potassium dichromate, chromium acetate, and ammonium chromate; one of the tungsten salts mentioned in step (4), namely sodium tungstate, calcium tungstate, and ammonium tungstate; one of the solvents mentioned in step (4), namely water, methanol, ethanol, ethylene glycol, isopropanol, n-butanol, n-hexane, cyclohexane, diethyl ether, and petroleum ether.

[0020] Preferably, the high-temperature calcination in step (5) is carried out at a heating rate of 1-20℃ / min, at 400-600℃, and for 3-6 hours; the volume fraction of hydrogen in the mixed gas is 1%-30%.

[0021] The application of wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalysts in hydrogen evolution reaction and oxygen evolution reaction, as described above.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] This invention utilizes wood-derived carbon materials as a carrier, and through vacuum impregnation, solvothermal reaction, and high-temperature calcination with metal salts, yields a wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst. The preparation process is simple, and the use of transition metals results in low cost. The obtained nickel-iron-molybdenum heterojunction water electrolysis hydrogen production catalyst exhibits good electrochemical catalytic activity for the hydrogen evolution reaction (HER) in alkaline solution, reaching -10 mA / cm². The Ni3Fe / MoO2 heterojunction supported on the wood-derived carbon substrate also demonstrates good electrochemical catalytic activity in alkaline solution, reaching -10 mA / cm². 2 The required overpotential is less than or equal to 150 mV, and the hydrogen evolution reaction (OER) reaches 300 mA / cm. 2 The required overpotential is less than or equal to 500mV, which lays the technical foundation for reducing the cost of industrial water electrolysis for hydrogen production. Attached Figure Description

[0024] Figure 1(a) is a transmission electron microscope (TEM) image of the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst prepared in Example 2 of the present invention. Figure 1 (b) is a high-resolution transmission electron microscope (HRTEM) image of the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst prepared in Example 2 of the present invention.

[0025] Figure 2 Field emission scanning electron microscope (SEM) images of different sizes of the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst prepared in Example 2 of this invention.

[0026] Figure 3 (a) A ring dark-field scanning transmission electron microscope (HAADF-STEM) of the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst prepared in Example 2 of the present invention. Figure 3 (b) is the energy dispersive X-ray spectroscopy (EDS) spectrum of the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst prepared in Example 2 of the present invention.

[0027] Figure 4 The image shows the X-ray diffraction (XRD) pattern of the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst prepared in Example 2 of this invention; where Ni3Fe / MoO2 / CW represents the XRD data of the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst prepared in Example 2 of this invention, and MoO2, C, and Ni3Fe are standard cards.

[0028] Figure 5 Polarization curve of hydrogen evolution reaction of the metal oxide-alloy heterojunction hydrogen production catalyst supported by wood-derived carbon in 1.0 mol / L potassium hydroxide solution;

[0029] Figure 6 Tafel slope diagram of hydrogen evolution of the catalyst of the present invention in 1.0 mol / L potassium hydroxide solution, based on a metal oxide-alloy heterojunction hydrogen production catalyst supported by wood-derived carbon.

[0030] Figure 7 Polarization curve of oxygen evolution reaction of the metal oxide-alloy heterojunction hydrogen production catalyst supported by wood-derived carbon in 1.0 mol / L potassium hydroxide solution;

[0031] Figure 8 The oxygen evolution Tafel slope diagram of the metal oxide-alloy heterojunction hydrogen production catalyst supported by wood-derived carbon in 1.0 mol / L potassium hydroxide solution;

[0032] in, Figure 5 ,Figure 6 , Figure 7 and Figure 8 The Ni3Fe / MoO2 / CW line represents the catalyst data prepared in Example 2, the Ni3Fe / CW line represents the catalyst data prepared in Comparative Example 1, and the MoO2 / CW line represents the catalyst data prepared in Comparative Example 2. Detailed Implementation

[0033] The specific embodiments are described in detail below with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Unless otherwise specified, the raw materials and reagents used in the embodiments are commercially available.

[0034] In this invention, the XRD testing method involves using a Minflex 600 X-ray diffractometer (Rigaku, Japan) to test the catalyst and determine its material composition. The conditions are as follows: the X-ray tube operates at 40 kV and 40 mA, with a scanning speed of 10° / min. -1 The 2θ scan range is 5-90°.

[0035] Example 1

[0036] A method for preparing a wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst, comprising the following steps:

[0037] (1) Weigh 4g of poplar wood chips, 130g of deionized water, 2g of acetic acid and 1g of sodium chlorite according to the mass ratio of wood chips, deionized water, acetic acid and sodium chlorite of 4:130:2:1. Heat the poplar wood chips in distilled water at 80℃ for 10 hours. Mix the weighed deionized water, acetic acid and sodium chlorite to obtain a mixed solution (this is the first addition of acetic acid and sodium chlorite). Put the poplar wood chips heated for 10 hours into the mixed solution and stir at 63rpm at 80℃ for 1 hour. Then add the same mass of acetic acid (2g newly weighed) and sodium chlorite (1g newly weighed) as the first time and continue stirring at 60rpm at 80℃. Finally, take out the wood chips and air dry them to obtain the pretreated wood chips.

[0038] (2) Dissolve 1.2g of nickel chloride in 40mL of deionized water to obtain a metal salt A solution with a concentration of 0.23mmol / mL. Put the pretreated wood chips in step (1) into the obtained metal salt A solution and vacuum impregnate for 8 hours. After impregnation, take out the wood chips, clean and dry them to obtain impregnated wood chips.

[0039] (3) Place the wood chips obtained after impregnation in step (2) in a tube furnace, introduce argon gas at 25 mL / min, maintain the heating rate at 10℃ / min to heat to 900℃ for high-temperature calcination, and hold for 3 hours to obtain sample B.

[0040] (4) Dissolve 300 mg ferric chloride and 200 mg vanadium chloride in 40 mL ethylene glycol to obtain a metal salt C solution with a concentration of 0.0078 mmol / mL. Put the metal salt C solution and sample B from step (2) into a reaction vessel and stir at 80°C and 64 rpm for 15 minutes to carry out a solvothermal reaction. The reaction temperature is 120°C and the reaction time is 30 hours. After the reaction is completed, cool to room temperature, take out the material obtained from the reaction vessel, clean and dry it to obtain a preliminary sample.

[0041] (5) Place the preliminary sample obtained in step (4) in a tube furnace and introduce a mixture of hydrogen and argon gas at 30 mL / min (the volume fraction of hydrogen in the mixture is 10%). Maintain a heating rate of 10 °C / min and heat to 600 °C for high-temperature calcination. Hold the temperature for 3 hours to obtain the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst.

[0042] Example 2

[0043] A method for preparing a wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst, comprising the following steps:

[0044] (1) Weigh 4g of poplar wood chips, 130g of deionized water, 1g of acetic acid and 1g of sodium chlorite according to the mass ratio of wood chips, deionized water, acetic acid and sodium chlorite of 4:130:1:1. Heat the poplar wood chips in distilled water at 80℃ for 10 hours. Mix the weighed deionized water, acetic acid and sodium chlorite to obtain a mixed solution (this is the first addition of acetic acid and sodium chlorite). Put the poplar wood chips heated for 10 hours into the mixed solution and stir at 65rpm at 80℃ for 1 hour. Then add the same mass of acetic acid (2g newly weighed) and sodium chlorite (1g newly weighed) as the first time and continue stirring at 70rpm at 80℃. Finally, take out the wood chips and air dry them to obtain the pretreated wood chips.

[0045] (2) Dissolve 2g of nickel nitrate in 50mL of deionized water to obtain a metal salt A solution with a concentration of 0.21mmol / mL. Put the pretreated wood chips in step (1) into the obtained metal salt A solution and vacuum impregnate for 8 hours. After impregnation, take out the wood chips, clean and dry them to obtain impregnated wood chips.

[0046] (3) Place the wood chips obtained after impregnation in step (2) in a tube furnace, introduce argon gas at 40 mL / min, maintain the heating rate at 5℃ / min to heat up to 800℃ for high-temperature calcination, and hold for 2 hours to obtain sample B.

[0047] (4) Dissolve 300 mg ferric nitrate and 400 mg sodium molybdate in 30 mL of deionized water to obtain a metal salt C solution with a concentration of 0.10 mmol / mL. Put the metal salt C solution and sample B from step (2) into a reaction vessel and stir at 80°C and 65 rpm for 15 minutes to carry out a solvothermal reaction. The reaction temperature is 180°C and the reaction time is 8 hours. After the reaction is completed, cool to room temperature, take out the material obtained from the reaction vessel, clean and dry it to obtain a preliminary sample.

[0048] (5) Place the preliminary sample obtained in step (4) in a tube furnace and introduce a mixture of hydrogen and argon gas at 40 mL / min (the volume fraction of hydrogen in the mixture is 5%). Maintain a heating rate of 5 °C / min and heat to 400 °C for high-temperature calcination. Hold for 3 hours to obtain the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst (Ni3Fe / MoO2 / CW).

[0049] Example 3

[0050] A method for preparing a wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst, comprising the following steps:

[0051] (1) Weigh 3g of balsa wood chips, 250g of deionized water, 5g of acetic acid and 4g of sodium chlorite according to the mass ratio of wood chips, deionized water, acetic acid and sodium chlorite of 3:250:5:4. Heat the balsa wood chips in distilled water at 80℃ for 10 hours. Mix the weighed deionized water, acetic acid and sodium chlorite to obtain a mixed solution (this is the first addition of acetic acid and sodium chlorite). Put the poplar wood chips heated for 10 hours into the mixed solution and stir at 68 rpm at 80℃ for 1 hour. Then add the same mass of acetic acid (5g newly weighed) and sodium chlorite (4g newly weighed) as the first time and continue stirring at 70 rpm at 80℃. Finally, take out the wood chips and air dry them to obtain the pretreated wood chips.

[0052] (2) Dissolve 1.9g of cobalt acetate in 50mL of methanol to obtain a metal salt A solution with a concentration of 0.21mmol / mL. Place the pretreated wood chips from step (1) into the obtained metal salt A solution and vacuum impregnate for 8 hours. After impregnation, take out the wood chips, clean and dry them to obtain impregnated wood chips.

[0053] (3) Place the wood chips obtained after impregnation in step (2) in a tube furnace, introduce argon gas at 45 mL / min, maintain the heating rate at 12℃ / min to heat to 900℃ for high-temperature calcination, and hold for 3 hours to obtain sample B.

[0054] (4) Dissolve 320 mg ferric nitrate and 300 mg ammonium tungstate in 30 mL of deionized water to obtain a metal salt C solution with a concentration of 0.07 mmol / mL. Put the metal salt C solution and sample B from step (2) into a reaction vessel and stir at 80°C and 68 rpm for 15 minutes to carry out a solvothermal reaction. The reaction temperature is 130°C and the reaction time is 18 hours. After the reaction is completed, cool to room temperature, take out the material obtained from the reaction vessel, clean and dry it to obtain a preliminary sample.

[0055] (5) Place the preliminary sample obtained in step (4) in a tube furnace and introduce a mixture of hydrogen and argon gas at 30 mL / min (the volume fraction of hydrogen in the mixture is 8%). Maintain a heating rate of 12 °C / min and heat to 500 °C for high-temperature calcination. Hold for 6 hours to obtain the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst.

[0056] Example 4

[0057] A method for preparing a wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst, comprising the following steps:

[0058] (1) According to the mass ratio of wood chips, deionized water, acetic acid and sodium chlorite of 3:150:1.2:1.5, weigh 3g of birch wood chips, 150g of deionized water, 1.2g of acetic acid and 1.5g of sodium chlorite. Heat the birch wood chips in distilled water at 80℃ for 10 hours. Mix the weighed deionized water, acetic acid and sodium chlorite to obtain a mixed solution (this is the first addition of acetic acid and sodium chlorite). Put the poplar wood chips heated for 10 hours into the mixed solution and stir at 70rpm at 80℃ for 1 hour. Then add the same mass of acetic acid (1.2g newly weighed) and sodium chlorite (1.5g newly weighed) as the first time and continue to stir at 61rpm at 80℃. Finally, take out the wood chips and air dry them to obtain the pretreated wood chips.

[0059] (2) Dissolve 1.9g of cobalt acetate in 40mL of petroleum ether to obtain a metal salt A solution with a concentration of 0.26mmol / mL. Place the pretreated wood chips from step (1) into the obtained metal salt A solution and vacuum impregnate for 8 hours. After impregnation, take out the wood chips, clean and dry them to obtain impregnated wood chips.

[0060] (3) Place the wood chips obtained after impregnation in step (2) in a tube furnace, introduce argon gas at 55 mL / min, maintain the heating rate at 12℃ / min to heat to 800℃ for high-temperature calcination, and hold for 6 hours to obtain sample B.

[0061] (4) Dissolve 440 mg manganese sulfate and 500 mg vanadium trioxide in 40 mL of isopropanol to obtain a metal salt C solution with a concentration of 0.15 mmol / mL. Put the metal salt C solution and sample B from step (2) into a reaction vessel and stir at 80°C and 70 rpm for 15 minutes to carry out a solvothermal reaction. The reaction temperature is 160°C and the reaction time is 20 hours. After the reaction is completed, cool to room temperature, take out the material obtained from the reaction vessel, clean and dry it to obtain a preliminary sample.

[0062] (5) Place the preliminary sample obtained in step (4) in a tube furnace and introduce a mixture of hydrogen and argon gas at 30 mL / min (the volume fraction of hydrogen in the mixture is 10%). Maintain a heating rate of 18 °C / min and heat to 550 °C for high-temperature calcination. Hold for 6 hours to obtain the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst.

[0063] Comparative Example 1

[0064] A method for preparing a wood-derived carbon-supported metal alloy hydrogen production catalyst, comprising the following steps:

[0065] (1) Weigh 4g of poplar wood chips, 130g of deionized water, 1g of acetic acid and 1g of sodium chlorite according to the mass ratio of wood chips, deionized water, acetic acid and sodium chlorite of 4:130:1:1. Heat the poplar wood chips in distilled water at 80℃ for 10 hours. Mix the weighed deionized water, acetic acid and sodium chlorite to obtain a mixed solution (this is the first addition of acetic acid and sodium chlorite). Put the poplar wood chips heated for 10 hours into the mixed solution and stir at 60 rpm at 80℃ for 1 hour. Then add the same mass of acetic acid (newly weighed 1g) and sodium chlorite (newly weighed 1g) as the first time and continue stirring at 60 rpm at 80℃. Finally, take out the wood chips and air dry them to obtain pretreated wood chips.

[0066] (2) Dissolve 1.1g of nickel sulfate in 30mL of deionized water to obtain a metal salt A solution with a concentration of 0.23mmol / mL. Put the pretreated wood chips in step (1) into the obtained metal salt A solution and vacuum impregnate for 8 hours. After impregnation, take out the wood chips, clean and dry them to obtain impregnated wood chips.

[0067] (3) Place the wood chips obtained after impregnation in step (2) in a tube furnace, introduce argon gas at 45 mL / min, maintain the heating rate at 5℃ / min to heat up to 900℃ for high-temperature calcination, and hold for 3 hours to obtain sample B.

[0068] (4) Dissolve 400 mg of ferric chloride in 30 mL of deionized water to obtain a metal salt C solution with a concentration of 0.08 mmol / mL. Put the metal salt C solution and sample B from step (2) into a reaction vessel and stir at 80°C and 64 rpm for 15 minutes to carry out a solvothermal reaction. The reaction temperature is 150°C and the reaction time is 24 hours. After the reaction is completed, cool to room temperature, take out the material obtained from the reaction vessel, clean and dry it to obtain a preliminary sample.

[0069] (5) Place the preliminary sample obtained in step (4) in a tube furnace and introduce a mixture of hydrogen and argon gas (the volume fraction of hydrogen in the mixture is 12%) at a rate of 40 mL / min. Maintain a heating rate of 12 °C / min and heat to 350 °C for high-temperature calcination. Hold for 5 hours to obtain the wood-derived carbon-supported metal alloy hydrogen production catalyst (-Ni3Fe / CW).

[0070] Comparative Example 2

[0071] A method for preparing a wood-derived carbon-supported metal oxide catalyst for hydrogen production, comprising the following steps:

[0072] (1) Weigh 4g of poplar wood chips, 130g of deionized water, 1g of acetic acid and 1g of sodium chlorite according to the mass ratio of wood chips, deionized water, acetic acid and sodium chlorite of 4:130:1:1. Heat the poplar wood chips in distilled water at 80℃ for 10 hours. Mix the weighed deionized water, acetic acid and sodium chlorite to obtain a mixed solution (this is the first addition of acetic acid and sodium chlorite). Put the poplar wood chips heated for 10 hours into the mixed solution and stir at 65rpm at 80℃ for 1 hour. Then add the same mass of acetic acid (2g newly weighed) and sodium chlorite (1g newly weighed) as the first time and continue stirring at 63rpm at 80℃. Finally, take out the wood chips and air dry them to obtain the pretreated wood chips.

[0073] (2) Dissolve 500 mg potassium molybdate in 40 mL of deionized water to obtain a metal salt A solution with a concentration of 0.05 mmol / mL. Place the pretreated wood chips from step (1) into the obtained metal salt A solution and vacuum impregnate for 8 hours. After impregnation, take out the wood chips, clean and dry them to obtain impregnated wood chips.

[0074] (3) Place the wood chips obtained after impregnation in step (2) in a tube furnace, introduce argon gas at 35 mL / min, maintain the heating rate at 10℃ / min to heat up to 800℃ for high-temperature calcination, and hold for 4 hours to obtain sample B.

[0075] (4) Place sample B in a tube furnace and introduce a mixture of hydrogen and argon at 25 mL / min (the volume fraction of hydrogen in the mixture is 10%). Maintain a heating rate of 15 °C / min and heat to 450 °C for high-temperature calcination. Hold the temperature for 3 hours to obtain the wood-derived carbon-supported metal oxide hydrogen production catalyst (-MoO2 / CW).

[0076] Table 1. Electrochemical hydrogen evolution performance in potassium hydroxide solution

[0077] Treatment -10 mA / cm 2 of the potential Tafel slope Comparative Example 1 - 149 mV 128 mV / dec Comparative Example 2 - 211 mV 179 mV / dec Example 2 - 45 mV 76 mV / dec

[0078] Table 2. Electrochemical oxygen evolution performance in potassium hydroxide solution

[0079] Treatment 300 mA / cm 2 of the potential Tafel slope Comparative Example 1 1.71 V 249 mV / dec Comparative Example 2 2.016V 282 mV / dec Example 2 1.481 V 79 mV / dec

[0080] Tables 1 and 2 show the catalysts prepared in Comparative Examples 1, 2, and 2 (catalyst dosage 0.2 cm). 2 The results were obtained by linear sweep voltammetry (LSV) tests in a 1.0 mol / L potassium hydroxide solution, and the results are listed in the table. The catalyst achieved a current of -10 mA / cm² in the 1.0 mol / L potassium hydroxide solution. 2 and 300mA / cm 2 The required potential for current density is calculated based on LSV, and the Tafel slope is listed in the table. The results are as follows: Figure 5 , Figure 5 , Figure 7 and Figure 8 As shown in Tables 1 and 2, the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst exhibits good hydrogen evolution reaction and oxygen evolution reaction performance in alkaline electrolytes.

[0081] Figure 1 It can be seen that the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst can form a metal alloy-metal oxide heterojunction interface. From Figure 2 It can be seen that the wood-derived carbon-supported metal oxide-alloy heterostructure hydrogen production catalyst exhibits a porous nanosheet morphology. From Figure 3 It can be seen that the metal and oxygen elements are uniformly distributed in the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst. From... Figure 4 (a) Figure 4 (b) Figure 4 (c) The material composition of Example 2, Comparative Example 2, and Comparative Example 1 can be seen respectively. From Figure 5 , Figure 6 , Figure 7 and Figure 8As can be seen from the above, the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst of this invention exhibits good hydrogen evolution reaction performance and oxygen evolution reaction performance in alkaline electrolytes, achieving -10 mA / cm². 2 The required potential for current density is less than 300mV, achieving 300mA / cm 2 The potential required for the current density is less than 2.1V.

[0082] Figures 5 to 8 In this context, -Ni3Fe / MoO2 / CW is the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst prepared in Example 2, -Ni3Fe / CW is the catalyst obtained in Comparative Example 1, and -MoO2 / CW is the catalyst obtained in Comparative Example 2.

[0083] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst, characterized in that: A wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst has a metal oxide-alloy heterojunction formed and supported on a wood-derived carbon substrate; the catalyst contains catalytically active metal elements and non-metal elements, wherein the catalytically active metal element is at least one of Ni, Fe, Mo, V, Co, W, and Cr; the non-metal element is C and / or O; wherein the active group is dispersed within the catalyst; The preparation method of the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst includes the following steps: (1) Heat the wood chips in water. First, add a mixed solution of water, acetic acid and sodium chlorite. Add the heated wood chips to the mixed solution and stir at 60-70 rpm at a certain temperature. Add the same mass of acetic acid and sodium chlorite as the first time and continue stirring at the same temperature at 60-70 rpm. Finally, remove the wood chips and air dry them to obtain pretreated wood chips. The mass ratio of the added wood chips to the water, acetic acid and sodium chlorite added in the first time is 1-5:100-300:1-10:1-10. (2) Dissolve metal salt A in a solvent to obtain metal salt A solution, put the pretreated wood chips in step (1) into the obtained metal salt A solution, impregnate, and after impregnation, take out the wood chips for cleaning and drying to obtain impregnated wood chips; the metal salt A is one of iron salt, nickel salt or cobalt salt; (3) The wood chips obtained after impregnation in step (2) are calcined at 800-1200 °C for 1-6 hours to obtain sample B; (4) Dissolve metal salt C in a solvent to obtain metal salt C solution. Put the metal salt C solution and the sample B from step (3) into a reaction vessel and stir to carry out a solvothermal reaction. After the reaction is completed, cool to room temperature, take out the material obtained from the reaction vessel, clean and dry to obtain a preliminary sample. The solvothermal reaction is carried out at 100-200 °C for 2-48 hours. The metal salt C is obtained by mixing metal salt D and metal salt E in any proportion. Metal salt D is one or two metal salts different from those in metal salt A solution, such as iron salt, nickel salt, and cobalt salt. Metal salt E is one of molybdenum salt, vanadium salt, chromium salt, and tungsten salt. (5) The preliminary sample obtained in step (4) is calcined at 200-900 °C by passing it through a mixture of hydrogen and argon gas for 1-6 hours to obtain a wood-derived carbon-supported metal oxide-alloy heterostructure hydrogen production catalyst.

2. The wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst according to claim 1, characterized in that: The XRD pattern of the catalyst shows diffraction peaks belonging to wood-derived carbon, metal alloys, and metal oxides.

3. The wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst according to claim 1, characterized in that: The mass ratio of the wood chips added in step (1) to the water, acetic acid and sodium chlorite added in the first step is 3-4:130-250:1-5:1-4; the wood chips mentioned in step (1) are one of pine, poplar, balsa wood, birch, fir, beech or eucalyptus.

4. The wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst according to claim 1, characterized in that: The nickel salt mentioned in step (2) is nickel chloride, nickel acetylacetonate, nickel acetate, nickel bromide, nickel iodide, nickel sulfate, nickel nitrate, and nickel ammonium sulfate; the cobalt salt mentioned in step (2) is one of cobalt chloride, cobalt sulfate, cobalt nitrate, cobalt carbonate, cobalt acetate, cobalt oxalate, cobalt phosphate, cobalt bromide, cobalt iodide, and cobalt sulfide; the iron salt mentioned in step (2) is one of ferric chloride, ferric sulfate, ferric nitrate, ferric carbonate, ferric oxalate, ferric phosphate, ferric bromide, ferric iodide, ferrous sulfate, ferric sulfate, ferrous nitrate, and ferrous chloride; the solvents mentioned in steps (2) and (4) are water, methanol, ethanol, ethylene glycol, isopropanol, n-butanol, n-hexane, cyclohexane, diethyl ether, and petroleum ether.

5. The wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst according to claim 1, characterized in that: The concentration of metal salt A solution in step (2) is 0.001-5 mmol / mL; in step (3), argon gas is introduced at 800-900℃ for high-temperature calcination, and the holding time is 2-6 hours.

6. The wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst according to claim 1, characterized in that: During the stirring process described in step (4), the stirring speed is 60-70 rpm, the temperature is 80 ℃, and the stirring time is 15 minutes; the solvothermal reaction is carried out at 120-180 ℃ for 8-20 hours; the concentrations of metal salt D and metal salt E described in step (4) are each 0.001-10 mmol / mL.

7. The wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst according to claim 1, characterized in that: The nickel salt mentioned in step (4) is nickel chloride, nickel acetylacetonate, nickel acetate, nickel bromide, nickel iodide, nickel sulfate, nickel nitrate, or nickel ammonium sulfate; the cobalt salt mentioned in step (4) is one of cobalt chloride, cobalt sulfate, cobalt nitrate, cobalt carbonate, cobalt acetate, cobalt oxalate, cobalt phosphate, cobalt bromide, cobalt iodide, or cobalt sulfide; the iron salt mentioned in step (4) is one of ferric chloride, ferric sulfate, ferric nitrate, ferric carbonate, ferric oxalate, ferric phosphate, ferric bromide, ferric iodide, ferrous sulfate, ferric sulfate, ferrous nitrate, or ferrous chloride. The molybdenum salt mentioned in step (4) is one of sodium molybdate, ammonium molybdate, calcium molybdate, potassium molybdate, ammonium hydrogen molybdate, ammonium phosphomolybdate, and molybdenum pentachloride; the vanadium salt mentioned in step (4) is one of vanadium sulfate, vanadium chloride, vanadium nitrate, sodium metavanadate, potassium metavanadate, vanadium pentoxide, ammonium vanadate, vanadium trioxide, and vanadium oxysulfate; the chromium salt mentioned in step (4) is one of chromium nitrate, potassium chromate, potassium dichromate, chromium acetate, and ammonium chromate; the tungsten salt mentioned in step (4) is one of sodium tungstate, calcium tungstate, and ammonium tungstate.

8. The wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst according to claim 1, characterized in that: The high-temperature calcination in step (5) is carried out at a heating rate of 1-20 ℃ / min, at 400-600 ℃, and for 3-6 hours; the volume fraction of hydrogen in the mixed gas is 1%-30%.

9. The application of the wood-derived carbon-supported metal oxide-alloy heterojunction hydrogen production catalyst as described in any one of claims 1-8 in hydrogen evolution reaction and oxygen evolution reaction.

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