Anion exchange membrane electrolysis catalyst as well as preparation method and application thereof
By supporting cerium sulfide nanoparticles on the surface of graphene oxide and synthesizing RuS2-CeS2 composite sulfides, the problems of poor activity of non-precious metal-based catalysts and high cost of noble metal catalysts in the prior art are solved, and high activity, low overpotential and low cost anion exchange membrane electrolytic catalysts are achieved.
Patent Information
- Application Number
- CN202510297134.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-13
- Publication Date
- 2025-05-13
AI Technical Summary
The existing non-precious metal-based anion exchange membrane electrolytic catalyst has poor electrocatalytic activity in hydrogen evolution reaction and requires high overpotentials. The cost of precious metal catalysts is high, which limits its industrial application.
Graphene oxide was used as a support, and the cerium sulfide nanoparticles were supported on the surface of graphene oxide through hydrothermal reaction, and RuS2-CeS2 composite sulfide was synthesized with a ruthenium source to serve as anion exchange membrane electrolytic catalyst.
The electrocatalytic hydrogen evolution activity of the catalyst is improved, the overpotential is reduced, the electrolytic stability is enhanced, the amount of noble metal ruthenium is reduced, and the preparation cost of the catalyst is reduced.
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of electrocatalysts, and in particular to an anion exchange membrane electrolysis catalyst and a preparation method and application thereof. Background Art
[0002] Anion exchange membrane electrolysis, or AEM electrolysis, is a highly efficient water electrolysis hydrogen production technology. The core components of AEM electrolysis include anion exchange membrane (for conducting OH - ions) and catalysts. Anion exchange membrane electrolysis catalyst is a catalyst used in the process of electrolyzing water to produce hydrogen. Its main function is to increase the reaction rate of oxygen evolution reaction at the anode and hydrogen evolution reaction at the cathode, reduce overpotential, and thus improve the efficiency of water decomposition and the production of hydrogen. The working principle of anion exchange membrane electrolysis catalyst is to utilize the selective transmission characteristics of anion exchange membrane to enable hydrogen ions to be effectively transmitted to the cathode, thereby promoting the generation of hydrogen, while preventing the transmission of cations and reducing the generation of oxygen, thereby increasing the production of hydrogen and reducing energy loss.
[0003] At present, the existing anion exchange membrane electrolysis catalysts include non-precious metal-based catalysts, such as NiFe alloy, nickel-iron layered double hydroxide, CoFe alloy, etc., spinel / perovskite structure oxides, metal phosphides, metal sulfides, metal nitrides, etc.; precious metal-based catalysts include platinum / carbon composite materials, precious metals iridium and ruthenium. For the catalysts in the above-mentioned prior art, although precious metals as catalysts have excellent activity and stability and good catalytic effects, the use of precious metal catalysts alone is expensive and not conducive to industrial development. For non-precious metal-based catalysts, their electrocatalytic activity in the hydrogen evolution reaction is poor, and the required overpotential is relatively high. Summary of the invention
[0004] The present invention provides an anion exchange membrane electrolysis catalyst and a preparation method and application thereof, which effectively solve the technical problems of poor electrocatalytic activity of non-precious metal-based catalysts in hydrogen evolution reaction, high required overpotential and high cost of precious metal catalysts, and at the same time provides an anion exchange membrane electrolysis catalyst with more reaction active sites, low required overpotential and better electrolysis stability.
[0005] The first object of the present invention is to provide a method for preparing an anion exchange membrane electrolysis catalyst, comprising the following steps:
[0006] A sulfur source and a soluble cerium salt are added to a graphene oxide dispersion, and a hydrothermal reaction is carried out at 120° C. to 280° C. to obtain cerium sulfide nanoparticles. At the same time, cerium atoms and C atoms in graphene oxide form Ce-C bonds, and the cerium sulfide nanoparticles are in situ loaded on the surface of graphene oxide to obtain a CeS2 / graphene oxide composite material.
[0007] The CeS2 / graphene oxide composite material and the ruthenium source are dispersed in water and mixed to obtain a Ru / CeS2 / graphene oxide precursor. The Ru / CeS2 / graphene oxide precursor is heated to 380°C to 520°C in a sulfur atmosphere, annealed, and the ruthenium source is converted into RuS2, and the RuS2-CeS2 composite sulfide is formed with CeS2 and loaded on graphene oxide to obtain an anion exchange membrane electrolysis catalyst.
[0008] As a preferred implementation, the mass ratio of the cerium sulfide nanoparticles to graphene oxide is 1:0.8-1.5.
[0009] As a preferred embodiment, the molar ratio of the soluble cerium salt to the sulfur source is 1:2 to 2.5.
[0010] As a preferred embodiment, the mass ratio of the CeS2 / graphene oxide composite material to the ruthenium source is 1:0.3-1.
[0011] As a preferred embodiment, before annealing, sulfur is heated at 25° C. to 35° C. for 30 min to 60 min to form a sulfur atmosphere.
[0012] As a preferred embodiment, the hydrothermal reaction time is 0.5h to 3h.
[0013] As a preferred implementation manner, the annealing time is 1 h to 4 h.
[0014] As a preferred embodiment, the sulfur source is thiourea or thioacetamide, the soluble cerium salt is CeCl3·7H2O or Ce(NO3)3·6H2O, and the ruthenium source is ruthenium trichloride.
[0015] The second object of the present invention is to provide an anion exchange membrane electrolysis catalyst prepared by the above preparation method.
[0016] The third object of the present invention is to provide an application of the above anion exchange membrane electrolysis catalyst in electrocatalytic hydrogen production.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] The invention provides a method for preparing an anion exchange membrane electrolysis catalyst. The method comprises the following steps: adding a sulfur source and a soluble cerium salt to a graphene oxide dispersion to generate a hydrothermal reaction to obtain cerium sulfide nanoparticles, and simultaneously cerium atoms and C atoms in the graphene oxide form Ce-C bonds, and the cerium sulfide nanoparticles are in situ loaded on the surface of the graphene oxide to obtain a CeS2 / graphene oxide composite material; the CeS2 / graphene oxide composite material and a ruthenium source are dispersed in water, mixed to obtain a Ru / CeS2 / graphene oxide precursor, and the Ru / CeS2 / graphene oxide precursor is subjected to a temperature-raising annealing treatment in a sulfur atmosphere to convert the ruthenium source into RuS2, and the RuS2-CeS2 composite sulfide is formed with CeS2 and loaded on the graphene oxide to obtain an anion exchange membrane electrolysis catalyst. The present invention uses graphene oxide as a carrier and loads cerium sulfide nanoparticles on the surface of graphene oxide, which not only promotes the composite material to expose more active sites, but also the loaded cerium sulfide nanoparticles effectively regulate the electronic structure of the graphene oxide surface, improve the composite material's ability to adsorb and desorb hydrogen atoms, and thus improve the activity of the electrocatalytic hydrogen evolution reaction. Furthermore, in the structure of the CeS2 / graphene oxide composite material, by converting the ruthenium-containing compound into RuS2, on the one hand, the RuS2-CeS2 composite sulfide formed by RuS2 and CeS2 greatly reduces the overpotential of the anion exchange membrane electrolysis catalyst, and on the other hand, during annealing, the CeS2 / graphene oxide composite material exposed in a sulfur atmosphere forms a Ce-S-Ru bond with the ruthenium-containing compound, so that the composite material is more tightly combined, thereby improving the electrocatalytic hydrogen evolution performance and stability of the anion exchange membrane electrolysis catalyst under alkaline conditions.
[0019] The preparation method of the anion exchange membrane electrolysis catalyst of the present invention is simple. Graphene oxide is used as a carrier and transition metal cerium is introduced, which reduces the amount of precious metal ruthenium used, greatly reduces the preparation cost of the catalyst, is conducive to large-scale production, and has good application prospects in the field of hydrogen production by electrolysis of water. DETAILED DESCRIPTION
[0020] In order to enable those skilled in the art to better understand the technical solution of the present invention and implement it, the present invention is further described below in conjunction with specific examples and data, but the examples are not intended to limit the present invention. The following test methods and detection methods, unless otherwise specified, are conventional methods; the reagents and raw materials, unless otherwise specified, are commercially available.
[0021] In view of the technical problems that when pure precious metals and their oxides are used as catalysts, the cost is high, and when non-precious metal catalysts are used in hydrogen evolution reaction, the electrocatalytic activity is poor, the required overpotential is high, and long-term stable operation cannot be performed, the present invention provides an anion exchange membrane electrolysis catalyst and a preparation method and application thereof.
[0022] The technical solution of the present invention is analyzed and explained in detail below.
[0023] The present invention provides a method for preparing an anion exchange membrane electrolysis catalyst, comprising the following steps:
[0024] A sulfur source and a soluble cerium salt are added to a graphene oxide dispersion, and a hydrothermal reaction is carried out at 120° C. to 280° C. for 0.5 h to 3 h to obtain cerium sulfide nanoparticles. At the same time, cerium atoms and C atoms in graphene oxide form Ce-C bonds, and the cerium sulfide nanoparticles are in situ loaded on the surface of graphene oxide to obtain a CeS2 / graphene oxide composite material;
[0025] The CeS2 / graphene oxide composite material and the ruthenium source are dispersed in water and mixed to obtain a Ru / CeS2 / graphene oxide precursor. In a sulfur atmosphere, the Ru / CeS2 / graphene oxide precursor is heated to 380°C to 520°C and annealed for 1h to 4h to convert the ruthenium source into RuS2, and the RuS2-CeS2 composite sulfide is formed with CeS2 and loaded on graphene oxide to obtain an anion exchange membrane electrolysis catalyst.
[0026] In order to further increase the active sites on the surface of graphene oxide, improve the electronic structure of the surface of graphene oxide, and thus improve the electrocatalytic hydrogen evolution activity of the composite material, the mass ratio of the cerium sulfide nanoparticles to the graphene oxide is 1:0.8-1.5. The loading amount of the cerium sulfide nanoparticles on the surface of graphene oxide has a great influence on the adsorption and desorption performance of H atoms of the composite material in the hydrogen evolution reaction. If it is lower than the ratio of 0.8 here, the loading amount of the cerium sulfide nanoparticles is too low, and the efficiency of the hydrogen evolution reaction is slightly improved. If it is higher than 1.5 defined here, the loading amount of the cerium sulfide nanoparticles is high, and the cerium sulfide nanoparticles are stacked on the surface of graphene oxide. Although its performance is not affected, the activity of catalytic hydrogen evolution is basically the same as the mass ratio of 1:1.5, and there is no obvious improvement effect on the catalytic activity.
[0027] It should be noted that the graphene oxide dispersion used in the present invention is a dispersion of graphene oxide in dimethylformamide, and the concentration of graphene oxide is 5 mg / mL.
[0028] In order to obtain cerium sulfide with higher purity, the molar ratio of the soluble cerium salt to the sulfur source is 1:2 to 2.5. In the above-defined molar ratio, the sulfur source is excessive, and the soluble cerium salt and the sulfur source are hydrothermally reacted to obtain cerium sulfide, and the excess sulfur source is removed in the reaction solution.
[0029] In order to further reduce the overpotential of the prepared catalyst and improve the electrolytic stability of the catalyst, the mass ratio of the CeS2 / graphene oxide composite material to the ruthenium source is 1:0.3-1.
[0030] In order to provide a sulfur atmosphere during the annealing process, sulfur is heated at 25°C to 35°C for 30min to 60min to form a sulfur atmosphere before annealing.
[0031] It should be noted that the sulfur source is thiourea or thioacetamide, the soluble cerium salt is CeCl3·7H2O or Ce(NO3)3·6H2O, and the ruthenium source is ruthenium trichloride.
[0032] The technical effects of the present invention are described below through specific embodiments and comparative examples.
[0033] Example 1
[0034] A method for preparing an anion exchange membrane electrolysis catalyst comprises the following steps:
[0035] S1, Ce(NO3)3·6H2O and thiourea were added to the graphene oxide dispersion in a molar ratio of 1:2, and hydrothermally reacted at 120°C for 3h to obtain cerium sulfide nanoparticles, which were in situ loaded on the surface of graphene oxide, filtered to obtain a primary product, and washed with deionized water to obtain a CeS2 / graphene oxide composite material. After loading, the mass ratio of cerium sulfide nanoparticles to graphene oxide was 1:1.5.
[0036] S2, the CeS2 / graphene oxide composite material and ruthenium trichloride are dispersed in water at a mass ratio of 1:0.3, and mixed to obtain a Ru / CeS2 / graphene oxide precursor, sulfur is heated at 35°C for 30 minutes in a sealed tube furnace to form a sulfur atmosphere, and then the Ru / CeS2 / graphene oxide precursor is heated to 380°C and annealed for 4 hours to convert the ruthenium source into RuS2, and form a RuS2-CeS2 composite sulfide with CeS2 to be loaded on graphene oxide, and then cooled to room temperature, filtered, washed, and dried to obtain an anion exchange membrane electrolysis catalyst.
[0037] Example 2
[0038] A method for preparing an anion exchange membrane electrolysis catalyst comprises the following steps:
[0039] S1, Ce(NO3)3·6H2O and thiourea were added to the graphene oxide dispersion at a molar ratio of 1:2.5, and hydrothermally reacted at 280°C for 0.5h to obtain cerium sulfide nanoparticles, which were in situ loaded on the surface of graphene oxide, filtered to obtain a primary product, and washed with deionized water to obtain a CeS2 / graphene oxide composite material. After loading, the mass ratio of cerium sulfide nanoparticles to graphene oxide was 1:0.8.
[0040] S2, the CeS2 / graphene oxide composite material and ruthenium trichloride are dispersed in water at a mass ratio of 1:1, and mixed to obtain a Ru / CeS2 / graphene oxide precursor, sulfur is heated at 25°C for 60 minutes in a sealed tube furnace to form a sulfur atmosphere, and then the Ru / CeS2 / graphene oxide precursor is heated to 520°C and annealed for 1 hour to convert the ruthenium source into RuS2, and form a RuS2-CeS2 composite sulfide with CeS2 to be loaded on graphene oxide, and then cooled to room temperature, filtered, washed, and dried to obtain an anion exchange membrane electrolysis catalyst.
[0041] Example 3
[0042] A method for preparing an anion exchange membrane electrolysis catalyst comprises the following steps:
[0043] S1, Ce(NO3)3·6H2O and thiourea were added to the graphene oxide dispersion in a molar ratio of 1:2, and hydrothermally reacted at 200°C for 2.5h to obtain cerium sulfide nanoparticles, which were in situ loaded on the surface of graphene oxide, filtered to obtain a primary product, and washed with deionized water to obtain a CeS2 / graphene oxide composite material. After loading, the mass ratio of cerium sulfide nanoparticles to graphene oxide was 1:1.
[0044] S2, the CeS2 / graphene oxide composite material and ruthenium trichloride are dispersed in water at a mass ratio of 1:0.8, and mixed to obtain a Ru / CeS2 / graphene oxide precursor, sulfur is heated at 30°C for 50 minutes in a sealed tube furnace to form a sulfur atmosphere, and then the Ru / CeS2 / graphene oxide precursor is heated to 450°C and annealed for 3 hours to convert the ruthenium source into RuS2, and form a RuS2-CeS2 composite sulfide with CeS2 to be loaded on graphene oxide, and then cooled to room temperature, filtered, washed, and dried to obtain an anion exchange membrane electrolysis catalyst.
[0045] Example 4
[0046] A method for preparing an anion exchange membrane electrolysis catalyst comprises the following steps:
[0047] S1, Ce(NO3)3·6H2O and thiourea were added to the graphene oxide dispersion in a molar ratio of 1:2.3, and hydrothermally reacted at 180°C for 2.5h to obtain cerium sulfide nanoparticles, which were in situ loaded on the surface of graphene oxide, filtered to obtain a primary product, and washed with deionized water to obtain a CeS2 / graphene oxide composite material. After loading, the mass ratio of cerium sulfide nanoparticles to graphene oxide was 1:1.2.
[0048] S2, the CeS2 / graphene oxide composite material and ruthenium trichloride are dispersed in water at a mass ratio of 1:0.5, and mixed to obtain a Ru / CeS2 / graphene oxide precursor, sulfur is heated at 30°C for 40 minutes in a sealed tube furnace to form a sulfur atmosphere, and then the Ru / CeS2 / graphene oxide precursor is heated to 400°C and annealed for 2 hours to convert the ruthenium source into RuS2, and form a RuS2-CeS2 composite sulfide with CeS2 to be loaded on graphene oxide, and then cooled to room temperature, filtered, washed, and dried to obtain an anion exchange membrane electrolysis catalyst.
[0049] Example 5
[0050] A method for preparing an anion exchange membrane electrolysis catalyst comprises the following steps:
[0051] S1, Ce(NO3)3·6H2O and thiourea were added to the graphene oxide dispersion at a molar ratio of 1:2.5, and hydrothermally reacted at 220°C for 2h to obtain cerium sulfide nanoparticles, which were in situ loaded on the surface of graphene oxide, filtered to obtain a primary product, and washed with deionized water to obtain a CeS2 / graphene oxide composite material. After loading, the mass ratio of cerium sulfide nanoparticles to graphene oxide was 1:1.
[0052] S2, the CeS2 / graphene oxide composite material and ruthenium trichloride are dispersed in water at a mass ratio of 1:1, and mixed to obtain a Ru / CeS2 / graphene oxide precursor, sulfur is heated at 35°C for 60 minutes in a sealed tube furnace to form a sulfur atmosphere, and then the Ru / CeS2 / graphene oxide precursor is heated to 480°C and annealed for 1.5 hours to convert the ruthenium source into RuS2, and form a RuS2-CeS2 composite sulfide with CeS2 to be loaded on graphene oxide, and then cooled to room temperature, filtered, washed, and dried to obtain an anion exchange membrane electrolysis catalyst.
[0053] Example 6
[0054] A method for preparing an anion exchange membrane electrolysis catalyst comprises the following steps:
[0055] S1, Ce(NO3)3·6H2O and thiourea were added to the graphene oxide dispersion in a molar ratio of 1:2, and hydrothermally reacted at 240°C for 1.5h to obtain cerium sulfide nanoparticles, which were in situ loaded on the surface of graphene oxide, filtered to obtain a primary product, and washed with deionized water to obtain a CeS2 / graphene oxide composite material. After loading, the mass ratio of cerium sulfide nanoparticles to graphene oxide was 1:1.
[0056] S2, the CeS2 / graphene oxide composite material and ruthenium trichloride are dispersed in water at a mass ratio of 1:0.6, and mixed to obtain a Ru / CeS2 / graphene oxide precursor, sulfur is heated at 30°C for 30 minutes in a sealed tube furnace to form a sulfur atmosphere, and then the Ru / CeS2 / graphene oxide precursor is heated to 500°C and annealed for 2 hours to convert the ruthenium source into RuS2, and form a RuS2-CeS2 composite sulfide with CeS2 to be loaded on graphene oxide, and then cooled to room temperature, filtered, washed, and dried to obtain an anion exchange membrane electrolysis catalyst.
[0057] In order to further illustrate the technical effect of the present invention, the present invention is also provided with a comparative example, as follows:
[0058] Comparative Example 1
[0059] Compared with Example 3, the difference is that the mass ratio of the loaded cerium sulfide nanoparticles to graphene oxide is adjusted from 1:1 to 1:2.5, that is, the loading amount of the cerium sulfide nanoparticles is reduced.
[0060] A method for preparing an anion exchange membrane electrolysis catalyst comprises the following steps:
[0061] S1, Ce(NO3)3·6H2O and thiourea were added to the graphene oxide dispersion in a molar ratio of 1:2, and hydrothermally reacted at 200°C for 2.5h to obtain cerium sulfide nanoparticles, which were in situ loaded on the surface of graphene oxide, filtered to obtain a primary product, and washed with deionized water to obtain a CeS2 / graphene oxide composite material. After loading, the mass ratio of cerium sulfide nanoparticles to graphene oxide was 1:2.5.
[0062] S2, the CeS2 / graphene oxide composite material and ruthenium trichloride are dispersed in water at a mass ratio of 1:0.8, and mixed to obtain a Ru / CeS2 / graphene oxide precursor, sulfur is heated at 30°C for 50 minutes in a sealed tube furnace to form a sulfur atmosphere, and then the Ru / CeS2 / graphene oxide precursor is heated to 450°C and annealed for 3 hours to convert the ruthenium source into RuS2, and form a RuS2-CeS2 composite sulfide with CeS2 to be loaded on graphene oxide, and then cooled to room temperature, filtered, washed, and dried to obtain an anion exchange membrane electrolysis catalyst.
[0063] Comparative Example 2
[0064] Compared with Example 3, the difference is that no cerium sulfide nanoparticles are loaded.
[0065] A method for preparing an anion exchange membrane electrolysis catalyst comprises the following steps:
[0066] According to the mass ratio of graphene oxide to ruthenium trichloride of 1:0.8, ruthenium trichloride was added to the graphene oxide dispersion and mixed to obtain a Ru / graphene oxide precursor. Sulfur was heated at 30°C for 50 minutes in a sealed tube furnace to form a sulfur atmosphere. The Ru / graphene oxide precursor was then heated to 450°C and annealed for 3 hours to convert the ruthenium source into RuS2 and load it on the graphene oxide. The product was cooled to room temperature, filtered, washed and dried to obtain an anion exchange membrane electrolysis catalyst.
[0067] Comparative Example 3
[0068] Compared with Example 3, the difference is that the mass ratio of CeS2 / graphene oxide composite material to ruthenium trichloride is adjusted from 1:0.8 to 1:0.1.
[0069] A method for preparing an anion exchange membrane electrolysis catalyst comprises the following steps:
[0070] S1, Ce(NO3)3·6H2O and thiourea were added to the graphene oxide dispersion in a molar ratio of 1:2, and hydrothermally reacted at 200°C for 2.5h to obtain cerium sulfide nanoparticles, which were in situ loaded on the surface of graphene oxide, filtered to obtain a primary product, and washed with deionized water to obtain a CeS2 / graphene oxide composite material. After loading, the mass ratio of cerium sulfide nanoparticles to graphene oxide was 1:1.
[0071] S2, according to a mass ratio of 1:0.1, the CeS2 / graphene oxide composite material and ruthenium trichloride are dispersed in water, mixed to obtain a Ru / CeS2 / graphene oxide precursor, sulfur is heated at 30°C for 50 minutes in a sealed tube furnace to form a sulfur atmosphere, and then the Ru / CeS2 / graphene oxide precursor is heated to 450°C and annealed for 3 hours to convert the ruthenium source into RuS2, and form a RuS2-CeS2 composite sulfide with CeS2 to be loaded on graphene oxide, cooled to room temperature, filtered, washed, and dried to obtain an anion exchange membrane electrolysis catalyst.
[0072] Comparative Example 4
[0073] Compared with Example 3, the difference is that no ruthenium trichloride is added.
[0074] A method for preparing an anion exchange membrane electrolysis catalyst comprises the following steps:
[0075] S1, Ce(NO3)3·6H2O and thiourea were added to the graphene oxide dispersion in a molar ratio of 1:2, and hydrothermally reacted at 200°C for 2.5h to obtain cerium sulfide nanoparticles, which were in situ loaded on the surface of graphene oxide, filtered to obtain a primary product, and washed with deionized water to obtain a CeS2 / graphene oxide composite material. After loading, the mass ratio of cerium sulfide nanoparticles to graphene oxide was 1:1.
[0076] S2, heating sulfur at 30°C for 50 minutes in a sealed tube furnace to form a sulfur atmosphere, heating the CeS2 / graphene oxide composite material to 450°C, annealing for 3 hours, cooling to room temperature, filtering, washing, and drying to obtain an anion exchange membrane electrolysis catalyst.
[0077] Comparative Example 5
[0078] Compared with Example 3, the difference is that the sulfur atmosphere is adjusted to an air atmosphere.
[0079] A method for preparing an anion exchange membrane electrolysis catalyst comprises the following steps:
[0080] S1, Ce(NO3)3·6H2O and thiourea were added to the graphene oxide dispersion in a molar ratio of 1:2, and hydrothermally reacted at 200°C for 2.5h to obtain cerium sulfide nanoparticles, which were in situ loaded on the surface of graphene oxide, filtered to obtain a primary product, and washed with deionized water to obtain a CeS2 / graphene oxide composite material. After loading, the mass ratio of cerium sulfide nanoparticles to graphene oxide was 1:1.
[0081] S2, according to a mass ratio of 1:0.8, the CeS2 / graphene oxide composite material and ruthenium trichloride are dispersed in water, mixed to obtain a Ru / CeS2 / graphene oxide precursor, and the Ru / CeS2 / graphene oxide precursor is heated to 450°C in an air atmosphere, annealed for 3 hours, the ruthenium source is converted into RuO2, and a RuO2-CeS2 composite sulfide is formed with CeS2 and loaded on graphene oxide, cooled to room temperature, filtered, washed, and dried to obtain an anion exchange membrane electrolysis catalyst.
[0082] The electrochemical properties of the anion exchange membrane electrolysis catalysts prepared in Examples 1 to 6 and Comparative Examples 1 to 5 of the present invention were tested. First, in a 1 mol / L KOH solution, the linear sweep voltammetry technique of the electrochemical workstation was used to measure the hydrogen evolution current density of 250 mA cm -2 Furthermore, the electrochemical double layer capacitance (C dl) were tested and obtained from CV tests in the potential range of 0.184-0.284 V (vs. RHE) with scan rates of 10, 20, 30, 40, and 50 mV s -1 , record C dl The results of hydrogen evolution overpotential (η250) and electrochemical double layer capacitance are shown in Table 1.
[0083] Table 1 Electrochemical performance of anion exchange membrane electrolysis catalysts of the embodiments and comparative examples
[0084] Hydrogen evolution overpotential (η250) / V <![CDATA[C dl Value / mFcm -2 ]]> Example 1 0.152 108.2 Example 3 0.148 115.6 Example 5 0.150 110.8 Comparative Example 1 0.213 98.5 Comparative Example 2 0.328 72.4 Comparative Example 3 0.227 100.3 Comparative Example 4 0.362 85.0 Comparative Example 5 0.205 101.7
[0085] It can be seen from Table 1 that the anion exchange membrane electrolysis catalyst prepared by the present invention has better electrocatalytic activity and lower overpotential. The anion exchange membrane electrolysis catalyst of Example 3 has a lower overpotential at a current density of 250 mA·cm -2 The overpotential of hydrogen evolution (η250) is only 0.148V, C dl Value up to 115.6mF cm -2 Compared with Example 3, the electrochemical performance of the anion exchange membrane electrolysis catalysts prepared in Comparative Examples 1 to 5 is poor, and the specific reasons are as follows:
[0086] Comparative Examples 1 and 2 are respectively the case where the loading amount of cerium sulfide in Example 3 is reduced and the loading amount of cerium sulfide on graphene oxide is removed. The anion exchange membrane electrolysis catalyst of Comparative Example 1 is subjected to a current density of 250 mA·cm -2 The overpotential of hydrogen evolution (η250) is 0.213V, C dl The value is 115.6mF cm -2 The anion exchange membrane electrolysis catalyst of Comparative Example 2 was -2 The overpotential of hydrogen evolution (η250) is 0.328V, C dl The value is 72.4mF cm -2 . From the comparison of the above data, it can be seen that loading cerium sulfide nanoparticles on the graphene oxide carrier has a greater effect on improving the catalytic activity of the catalyst. After the reduction of the loading amount of cerium sulfide nanoparticles and the removal of cerium sulfide nanoparticles, the catalytic active sites of the composite material are reduced or the surface modification effect of cerium sulfide nanoparticles on graphene oxide is directly lost, thereby reducing the activity of the catalytic hydrogen evolution reaction and failing to achieve effective regulation of the electronic structure of the graphene oxide surface, resulting in a decrease in the adsorption and desorption ability of the composite material for hydrogen atoms, so the activity of the electrocatalytic hydrogen evolution reaction is reduced.
[0087] Comparative Examples 3 and 4 are respectively the case where the amount of ruthenium trichloride in Example 3 is reduced and the ruthenium trichloride is removed. The anion exchange membrane electrolysis catalyst of Comparative Example 3 is subjected to a current density of 250 mA·cm-2 The overpotential of hydrogen evolution (η250) is 0.227V, C dl The value is 100.3mF cm -2 The anion exchange membrane electrolysis catalyst of Comparative Example 4 was subjected to a current density of 250 mA·cm -2 The overpotential of hydrogen evolution (η250) is 0.362V, C dl The value is 85.0mF cm -2 . From the above data, it can be seen that in-situ growth of RuS2 on the CeS2 / graphene oxide composite material by annealing treatment and forming RuO2-CeS2 composite sulfide with CeS2 is of great significance for reducing the overpotential of the catalyst. In the structure of the CeS2 / graphene oxide composite material, the ruthenium-containing compound RuCl3 is converted into RuS2. Since the amount of RuCl3 in Comparative Example 3 and Comparative Example 4 is reduced or RuCl3 is directly removed, the amount of converted RuS2 is reduced or RuS2 cannot be obtained, thereby reducing the amount of RuS2-CeS2 composite sulfide formed by RuS2 and CeS2, which directly affects the effective regulation of the overpotential of the anion exchange membrane electrolysis catalyst. It can be seen that loading RuS2 can effectively reduce the overpotential of the anion exchange membrane electrolysis catalyst, thereby giving the catalyst better electrochemical properties.
[0088] Comparative Example 5 is to adjust the sulfur atmosphere in Example 3 to an air atmosphere, and obtain RuO2 after annealing. -2 The overpotential of hydrogen evolution (η250) is 0.205V, C dl The value is 101.7mF cm -2 Compared with the data of the catalyst in Example 3, the hydrogen evolution overpotential (η250) of the catalyst obtained by annealing RuO2 and CeS2 on the surface of graphene oxide in Comparative Example 5 is slightly higher than that of the catalyst in Example 3. dl The value is slightly lower than that of the catalyst in Example 3, so compared with RuS2, RuO2 has a more obvious effect on reducing the overpotential of the catalyst, and the CeS2 / graphene oxide composite material after treatment in an air atmosphere cannot form a Ce-S-Ru bond with the ruthenium-containing compound, thereby reducing the electrocatalytic hydrogen evolution performance and stability of the anion exchange membrane electrolysis catalyst under alkaline conditions.
[0089] In addition, when graphene oxide is used as a carrier, the effects of CeS2 or RuS2 on anion exchange membrane electrolysis catalysts are different. dl The value and the current density are 250mA·cm -2From the change in the hydrogen evolution overpotential (η250), it can be found that loading CeS2 has a greater effect on increasing the reaction active sites on the catalyst surface, while loading RuS2 has a greater effect on reducing the overpotential of the catalyst.
[0090] In addition, the stability of the anion exchange membrane electrolysis catalysts prepared in Examples 1 to 6 of the present invention was also tested. The anion exchange membrane electrolysis catalysts prepared in Examples 1 to 6 of the present invention were tested in an oxygen-saturated 1 mol / L KOH solution at 10 mA / cm 2 The catalytic activity can be maintained for more than 1000 h at the corresponding voltage of 100 mA / cm 2 The catalytic activity can be maintained for more than 2500 h at the voltage of 1.5 Å, which shows that the anion exchange membrane electrolysis catalyst prepared by the present invention has extremely excellent stability.
[0091] In summary, the anionic surfactant prepared by the present invention effectively improves the electrocatalytic hydrogen evolution activity and efficiency of the catalyst by loading CeS2 and RuS2 on the surface of graphene oxide. The preparation method of the anion exchange membrane electrolysis catalyst of the present invention is simple, using graphene oxide as a carrier and introducing transition metal cerium, reducing the amount of precious metal ruthenium, greatly reducing the preparation cost of the catalyst, facilitating large-scale production, and having good application prospects in the field of hydrogen production by electrolysis of water.
[0092] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.
Claims
1. A method for preparing an anion exchange membrane electrolysis catalyst, characterized in that: The following steps are involved: A sulfur source and a soluble cerium salt are added to a graphene oxide dispersion, and a hydrothermal reaction is carried out at 120° C. to 280° C. to obtain cerium sulfide nanoparticles. At the same time, cerium atoms and C atoms in graphene oxide form Ce-C bonds, and the cerium sulfide nanoparticles are in situ loaded on the surface of graphene oxide to obtain a CeS2 / graphene oxide composite material. The CeS2 / graphene oxide composite material and the ruthenium source are dispersed in water and mixed to obtain a Ru / CeS2 / graphene oxide precursor. The Ru / CeS2 / graphene oxide precursor is heated to 380°C to 520°C in a sulfur atmosphere, annealed, and the ruthenium source is converted into RuS2, and the RuS2-CeS2 composite sulfide is formed with CeS2 and loaded on graphene oxide to obtain an anion exchange membrane electrolysis catalyst.
2. The preparation method according to claim 1, characterized in that: The mass ratio of the cerium sulfide nanoparticles to graphene oxide is 1:0.8-1.
5.
3. The preparation method according to claim 1, characterized in that: The molar ratio of the soluble cerium salt to the sulfur source is 1:2 to 2.
5.
4. The preparation method according to claim 1, characterized in that: The mass ratio of the CeS2 / graphene oxide composite material to the ruthenium source is 1:0.3-1.
5. The preparation method according to claim 1, characterized in that: Before annealing, sulfur is heated at 25°C to 35°C for 30min to 60min to form a sulfur atmosphere.
6. The preparation method according to claim 1, characterized in that: The hydrothermal reaction time is 0.5h to 3h.
7. The preparation method according to claim 1, characterized in that: The annealing time is 1 h to 4 h.
8. The preparation method according to claim 1, characterized in that: The sulfur source is thiourea or thioacetamide, the soluble cerium salt is CeCl3·7H2O or Ce(NO3)3·6H2O, and the ruthenium source is ruthenium trichloride.
9. An anion exchange membrane electrolysis catalyst prepared by the preparation method according to any one of claims 1 to 8.
10. Use of the anion exchange membrane electrolysis catalyst according to claim 9 in electrocatalytic hydrogen production.