Preparation method of hydrogen production catalyst of multi-metal selenide

Abstract

The application discloses a preparation method of a multi-metal selenide hydrogen production catalyst. Corresponding nitrate is dissolved in water, and trimesic acid, 1,2,4-triazole and polyvinylpyrrolidone are dissolved in N,N-dimethylformamide to prepare an N,N-dimethylformamide mixed solution; the nitrate mixed solution and the N,N-dimethylformamide mixed solution are mixed and uniformly stirred, a metal organic gel is prepared through a hydrothermal reaction, and after centrifugation, washing and freeze-drying, the precursor powder is obtained through grinding; the precursor powder and SeO2 are mixed and dispersed in N,N-dimethylformamide, and ultrasonic mixing is performed until the mixture is uniformly dispersed; the prepared mixed solution is transferred into a Teflon reaction kettle; after the reaction is completed, the precipitate is washed with deionized water and ethanol and dried, and the catalyst is obtained. The application provides a preparation method of selenide used as a water decomposition reaction catalyst, reduces the preparation cost of the catalyst, and improves the water decomposition reaction performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of electrolytic water catalyst preparation, and particularly relates to a preparation method of a multi-metal selenide hydrogen production catalyst. BACKGROUND

[0002] Hydrogen energy is a clean, efficient and carbon-free secondary energy source, and is widely used, so increasing hydrogen energy utilization has become an important consensus for global low-carbon development.

[0003] At present, the method mainly used for hydrogen production in China is the fossil fuel hydrogen production method, but it is inevitable to depend on fossil fuels, which not only requires harsh reaction conditions such as high temperature and high pressure, but also emits greenhouse gases such as carbon dioxide, causing environmental pollution. Therefore, it is particularly important to find a mild, energy-saving and environmentally friendly hydrogen production method.

[0004] Water electrolysis hydrogen production technology has strong development potential. This technology uses water as raw material, and generates hydrogen and oxygen by electrolysis of water through direct current. Almost no CO2 is generated in the process, realizing the sustainable development of green hydrogen production with low energy consumption and no pollution emission in the synthesis process.

[0005] The water electrolysis reaction includes hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The HER and OER reaction kinetics are slow, and a high overpotential is required to drive the normal progress of the reaction, resulting in low energy conversion efficiency.

[0006] At present, Pt-based catalysts and IrO2, RuO2 are still considered to be the most effective catalysts for OER and HER reactions, but noble metal-based catalysts are high in cost, low in reserves, and have great limitations in commercial applications.

[0007] In addition, many current catalysts only optimize one of the two half-reactions, so it is urgent to develop efficient, stable and low-cost bifunctional electrocatalysts for full water splitting. SUMMARY

[0008] This section aims to summarize some aspects of the embodiments of the application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, abstract and title, and such simplifications or omissions cannot be used to limit the scope of the application.

[0009] In view of the above and / or problems existing in the prior art, the present application is proposed.

[0010] Therefore, the purpose of the present application is to overcome the deficiencies in the prior art and provide a preparation method of a multi-metal selenide hydrogen production catalyst.

[0011] To solve the above technical problems, the application provides a preparation method of a multi-metal selenide hydrogen production catalyst, which comprises the following steps,

[0012] Ni(NO3)2·6H2O, Co(NO3)2·6H2O, Cu(NO3)2·3H2O and Fe(NO3)3·9H2O are dissolved in water to prepare a nitrate mixed solution;

[0013] 1,2,4-triazole and polyvinylpyrrolidone are dissolved in N,N-dimethylformamide to prepare an N,N-dimethylformamide mixed solution;

[0014] The nitrate mixed solution and the N,N-dimethylformamide mixed solution are mixed and stirred uniformly, and a metal organic gel is prepared through hydrothermal reaction; after centrifugation, washing and freeze-drying, the precursor powder is obtained through grinding;

[0015] The precursor powder and SeO2 are mixed and dispersed in N,N-dimethylformamide, and the mixed solution is transferred into a Teflon reaction kettle and reacted at 200-240 ℃ for 20-24 h through ultrasonic mixing and dispersion;

[0016] After the reaction is completed, the precipitate is washed with deionized water and ethanol and dried, and the bifunctional water electrolysis hydrogen production catalyst is obtained.

[0017] As a preferred scheme of the preparation method, the molar ratio of Ni, Co, Cu and Fe in the nitrate mixed solution is 1-6:0.33-2:0.33-2:0.33-2.

[0018] As a preferred scheme of the preparation method, the total amount of metal and water in the nitrate mixed solution is 0.02:30 in mol:mL.

[0019] As a preferred scheme of the preparation method, the ratio of the trimesic acid, 1,2,4-triazole, polyvinylpyrrolidone and N,N-dimethylformamide is 4.2886 g:8.3721 g:4.0000 g:110 mL.

[0020] As a preferred scheme of the preparation method, the ratio of the total amount of metal and N,N-dimethylformamide in the mixing of the nitrate mixed solution and the N,N-dimethylformamide mixed solution is 0.02 mol:110 mL.

[0021] As a preferred scheme of the preparation method, the hydrothermal reaction temperature for preparing the metal organic gel is 90-100 ℃, and the reaction time is 4-6 h.

[0022] As a preferred solution of the preparation method, the precursor powder and SeO2 are mixed, and the mass ratio of the precursor powder to SeO2 is 0.5g:1.5g.

[0023] As a preferred solution of the preparation method, the precursor powder and SeO2 are mixed, and the precursor powder is dispersed in N,N-dimethylformamide, and the ratio of the precursor powder to N,N-dimethylformamide is 0.5g:60mL.

[0024] As a preferred solution of the preparation method, the precursor powder and SeO2 are mixed, and the precursor powder is dispersed in N,N-dimethylformamide, and the ratio of the precursor powder to N,N-dimethylformamide is 0.5g:60mL.

[0025] Still another object of the present application is to provide a hydrogen production catalyst prepared by the preparation method of the multi-metal selenium compound hydrogen production catalyst.

[0026] The present application has the following beneficial effects:

[0027] (1) The present application successfully applies the transition metal selenium compound such as Ni-based and Fe-based to the water decomposition reaction in a controllable manner, and has a high catalytic rate.

[0028] (2) The catalyst prepared by the present application in a controllable manner by combining the transition metal selenium compound such as Ni and Fe-based has high efficient catalytic HER and OER, and since two reactions require different active sites, it is challenging to control the composition to optimize the HER and OER dual functional activity, and the catalytic performance, especially the HER reaction, is significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0030] Figure 1 The XRD graph of the catalyst prepared in the embodiment of the present application.

[0031] Figure 2 The HRTEM graph of the catalyst prepared in the embodiment 1 of the present application.

[0032] Figure 3 The HER activity graph of the catalyst prepared in the embodiment of the present application.

[0033] Figure 4OER activity graph of the catalyst prepared in the embodiment of the present application.

[0034] Figure 5 HER activity graph of the catalyst prepared in Comparative Example 1 of the present application.

[0035] Figure 6 OER activity graph of the catalyst prepared in Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0036] In order to make the above objectives, characteristics and advantages of the present application more apparent, comprehensible and easily understood, the specific embodiments of the present application will be described in detail below with reference to the embodiments of the present application.

[0037] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other manners different from those described herein, and those skilled in the art can make similar generalizations without departing from the concept of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0038] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is independent or alternative to other embodiments.

[0039] The catalyst prepared in the present application is subjected to electrochemical test by using a three-electrode electrolytic cell reaction device to test its water splitting performance.

[0040] Electrochemical water splitting performance evaluation: The test is performed by using an electrochemical workstation (Shanghai Chenhua, CHI760E). In the three-electrode system, the working electrode uses a carbon paper loaded with the catalyst, the reference electrode uses an Ag / AgCl electrode, and the counter electrode uses a carbon rod. The device is tested at normal temperature and pressure with 1M KOH as the electrolyte:

[0041] First, 8mg of catalyst and 8mg of activated carbon are weighed, 1.5mL of N-methyl pyrrolidone and 0.1mL of NaFion solution are added, and the mixture is uniformly mixed by ultrasonic for 30min to prepare a catalyst suspension. The catalyst suspension is dropped on a carbon paper with a size of 0.5cm x 0.5cm and dried to prepare a working electrode with a catalyst loading of 0.24mgcm -2

[0042] Secondly, the HER and OER performances are tested respectively in a suitable potential range by using linear sweep method (LSV);

[0043] Subsequently, the CV curve is continuously tested at different scan rates;

[0044] ​Finally, the impedance of the catalyst was tested;

[0045] Current density based on the macroscopic area of the electrode 10 mA cm -2 As an index to evaluate the catalytic activity of the catalyst.

[0046] Example 1

[0047] (1) The total amount of metal was kept at 0.02 mol, and Ni(NO3)2·6H2O, Co(NO3)2·6H2O, Cu(NO3)2·3H2O and Fe(NO3)3·9H2O were weighed in a ratio of Ni:Co:Cu:Fe = 1:1:1:1 and dissolved in 30 mL of water. 8.3721 g of 1,2,4-triazole, 4.2886 g of trimesic acid and 4.0000 g of polyvinylpyrrolidone were dissolved in 110 mL of DMF. The two solutions were mixed evenly, heated to 90°C in a water bath, and reacted for 4h. After the reaction was completed, it was naturally cooled to room temperature. After centrifugal washing and freeze-drying, the precursor A1 was obtained.

[0048] (2) 0.5 g of A1 and 1.5 g of SeO2 were dispersed in 60 mL of DMF and ultrasonicated for 60 min.

[0049] (3) The mixed solution was transferred to a Teflon reaction kettle and reacted at 200°C for 24h.

[0050] (4) After the reaction was completed, the precipitate was washed with deionized water and ethanol three times, and the catalyst was obtained after drying at 80°C for 24h, named S1. The HRTEM image of the catalyst is shown in Figure 2 .

[0051] After the above catalyst was prepared into a working electrode for electrochemical water decomposition test, it was found that S1 had certain catalytic performance. For HER, the overpotential of the catalyst driving 10 mA cm -2 current density in 1M KOH electrolyte was 296mV. For OER, the overpotential of the catalyst driving 10 mA cm -2 current density in 1M KOH electrolyte was 330mV.

[0052] Example 2

[0053] (1) Keep the total amount of metal as 0.02 mol, take Ni(NO3)2·6H2O, Co(NO3)2·6H2O, Cu(NO3)2·3H2O and Fe(NO3)3·9H2O dissolved in 30 mL water in the proportion of Ni:Co:Cu:Fe = 1:2:2:2, take 8.3721 g 1,2,4-triazole, 4.2886 g trimesic acid and 4.0000 g polyvinylpyrrolidone dissolved in 110 mL DMF, mix the two solutions evenly, heat to 90℃ in water bath, react for 4 h, after the reaction is completed, naturally cool it to room temperature, centrifugal wash, freeze-drying to obtain the precursor A2.

[0054] (2) Disperse 0.5 g A2 and 1.5 g SeO2 in 60 mL DMF, ultrasonic for 60 min.

[0055] (3) Transfer the mixed solution to a Teflon reaction kettle, react at 200℃ for 24 h.

[0056] (4) After the reaction is completed, wash the precipitate with deionized water and ethanol three times, dry at 80℃ for 24 h to obtain the catalyst, named as S2.

[0057] After the above catalyst is prepared into a working electrode for electrochemical water decomposition test, it is found that S2 has certain catalytic performance. For HER, the overpotential of the catalyst driving 10 mA cm-2current density in 1M KOH electrolyte is 342 mV. For OER, the overpotential of the catalyst driving 10 mA cm-2current density in 1M KOH electrolyte is 330 mV. -2 -2

[0058] Example 3

[0059] (1) Keep the total amount of metal as 0.02 mol, take Ni(NO3)2·6H2O, Co(NO3)2·6H2O, Cu(NO3)2·3H2O and Fe(NO3)3·9H2O dissolved in 30 mL water in the proportion of Ni:Co:Cu:Fe = 1:1 / 3:1 / 3:1 / 3, take 8.3721 g 1,2,4-triazole, 4.2886 g trimesic acid and 4.0000 g polyvinylpyrrolidone dissolved in 110 mL DMF, mix the two solutions evenly, heat to 90℃ in water bath, react for 4 h, after the reaction is completed, naturally cool it to room temperature, centrifugal wash, freeze-drying to obtain the precursor A3.

[0060] (2) Disperse 0.5 g A3 and 1.5 g SeO2 in 60 mL DMF, ultrasonic for 60 min.

[0061] ​​(3) The mixed solution was transferred to a Teflon reactor, and reacted at 200 °C for 24 h.

[0062] (4) After the reaction was completed, the precipitate was washed with deionized water and ethanol three times, and the catalyst was obtained after drying at 80 °C for 24 h, and was named S3.

[0063] After the above catalyst was prepared into a working electrode for electrochemical water splitting test, it was found that the S3 catalyst had certain catalytic performance. For HER, the overpotential of the catalyst driving 10 mA cm-2current density in 1 M KOH electrolyte was 257 mV. For OER, the overpotential of the catalyst driving 10 mA cm-2current density in 1 M KOH electrolyte was 320 mV. -2 -2

[0064] Example 4

[0065] (1) The total amount of metal was kept at 0.02 mol, and Ni(NO3)2·6H2O, Co(NO3)2·6H2O, Cu(NO3)2·3H2O and Fe(NO3)3·9H2O were weighed according to the ratio of Ni:Co:Cu:Fe = 3:1 / 3:1 / 3:1 / 3, and dissolved in 30 mL of water. 8.3721 g of 1,2,4-triazole, 4.2886 g of trimesic acid and 4.0000 g of polyvinylpyrrolidone were dissolved in 110 mL of DMF, and the two solutions were mixed uniformly. The water bath was heated to 90 °C, and reacted for 4 h. After the reaction was completed, it was naturally cooled to room temperature, centrifuged, washed and freeze-dried to obtain the precursor A4.

[0066] (2) 0.5 g of A4 and 1.5 g of SeO2 were dispersed in 60 mL of DMF, and ultrasonic was performed for 60 min.

[0067] (3) The mixed solution was transferred to a Teflon reactor, and reacted at 200 °C for 24 h.

[0068] (4) After the reaction was completed, the precipitate was washed with deionized water and ethanol three times, and the catalyst was obtained after drying at 80 °C for 24 h, and was named S4.

[0069] After the above catalyst was prepared into a working electrode for electrochemical water splitting test. For HER, the overpotential of the catalyst driving 10 mA cm-2current density in 1 M KOH electrolyte was 246 mV. For OER, the overpotential of the catalyst driving 10 mA cm-2current density in 1 M KOH electrolyte was 320 mV. -2 -2

[0070] Example 5

[0071] ​​​​(1) Keep the total metal content at 0.02 mol. Weigh Ni(NO3)2·6H2O, Co(NO3)2·6H2O, Cu(NO3)2·3H2O and Fe(NO3)3·9H2O in a ratio of Ni:Co:Cu:Fe = 6:1 / 3:1 / 3:1 / 3 and dissolve them in 30 mL of water. Weigh 8.3721 g of 1,2,4-triazole, 4.2886 g of trimesic acid and 4.0000 g of polyvinylpyrrolidone and dissolve them in 110 mL of DMF. Mix the two solutions evenly and heat them in a water bath to 90 °C. React for 4 h. After the reaction is completed, allow them to cool naturally to room temperature. After centrifugation, washing and freeze-drying, the precursor A5 can be obtained.

[0072] (2) Disperse 0.5g A5 and 1.5g SeO2 in 60ml LDM and sonicate for 60min.

[0073] (3) Transfer the mixture to a Teflon reactor and react at 200°C for 24 hours.

[0074] (4) After the reaction is complete, the precipitate is washed three times with deionized water and ethanol, and dried at 80°C for 24 hours to obtain the catalyst, which is named S5.

[0075] The above catalyst was prepared as a working electrode and subjected to electrochemical water splitting tests. For HER, the catalyst was driven by 10 mA cm⁻¹ in 1 MKOH electrolyte. -2 The overpotential of the current density is 231mV.

[0076] For OER, the catalyst drives 10 mA cm⁻¹ in 1 M KOH electrolyte. -2 The overpotential of the current density is 320mV.

[0077] The parameters of A1-A5 obtained in Examples 1-5 are compared in Table 1.

[0078] Table 1

[0079] A1 NiCoCuFe = 1 : 1 : 1 : 1 A2 NiCoCuFe = 1 : 2 : 2 : 2 A3 NiCoCuFe = 1 : 1 / 3 : 1 / 3 : 1 / 3 A4 NiCoCuFe = 3 : 1 / 3 : 1 / 3 : 1 / 3 A5 NiCoCuFe = 6 : 1 / 3 : 1 / 3 : 1 / 3

[0080] The catalytic activity of selenization varies depending on the proportion of precursor used. (See attached image) Figure 1 The XRD patterns of samples S1-S5 are shown. All samples exhibit distinct diffraction peaks at (2θ) ~29.9°, ~33.5°, ~42.9°, ~50.6°, ~55.5°, and ~57.8°, which are in good agreement with the standard card for NiSe2 (PDF#88-1711). According to the attached... Figure 1 Appendix Figure 2 It can be seen that the selenide in Example 1 has a NiSe2-based topological structure. According to the appendix... Figure 3 and 4It can be seen that the catalytic performance, especially the HER reaction, is significantly improved with the increase of nickel content.

[0081] Comparative Example 1

[0082] The total amount of metal was kept at 0.02 mol, and the precursors of Ni:Co:Cu = 1:1:1, Co:Cu:Fe = 1:1:1, NiCoFe = 1:1:1 were prepared by the same method as in Example 1, named A6, A7 and A8, and the corresponding selenides were named S6, S7 and S8.

[0083] For HER, the overpotential of the catalyst driving 10 mA cm -2 current density in 1M KOH electrolyte was measured; for OER, the overpotential of the catalyst driving 10 mA cm -2 current density in 1M KOH electrolyte was measured.

[0084] The parameters of A6-A8 were compared, see Table 2, and the HER activity of the prepared catalysts was seen in Figure 5 , and the OER activity of the prepared catalysts was seen in Figure 6 .

[0085] Table 2

[0086] Precursor Ratio HER(h 10 )]]> OER(h 10 )]]> A6 NiCoCu = 1 : 1 : 1 308 mV 330 mV A7 CoCuFe = 1 : 1 : 1 350 mV 340 mV A8 NiCoFe = 1 : 1 : 1 424 mV 350 mV

[0087] As can be seen from Table 2, when the prepared catalysts lack one of Ni, Co, Cu and Fe, the catalytic HER and OER activities decrease.

[0088] It should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit it, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the present application.

Claims

1. A method for preparing a multi-metal selenide bifunctional hydrogen evolution catalyst, characterized in that: comprising, dissolving Ni(NO3)2·6H2O, Co(NO3)2·6H2O, Cu(NO3)2·3H2O and Fe(NO3)3·9H2O in water to prepare a nitrate mixed solution, wherein the molar ratio of Ni, Co, Cu and Fe is 1-6:0.33-2:0.33-2:0.33-2, and the total amount of metal is 0.02:30 in mol:mL with respect to water; dissolving trimesic acid, 1,2,4-triazole and polyvinylpyrrolidone in N,N-dimethylformamide to prepare an N,N-dimethylformamide mixed solution, wherein the ratio of trimesic acid, 1,2,4-triazole, polyvinylpyrrolidone and N,N-dimethylformamide is 4.2886g:8.3721g:4.0000g:110mL; mixing the nitrate mixed solution and the N,N-dimethylformamide mixed solution, stirring uniformly, and preparing a metal organic gel by hydrothermal reaction, and then grinding the precursor powder after centrifugation, washing and freeze-drying, wherein the ratio of the total amount of metal to N,N-dimethylformamide is 0.02mol:110mL, the hydrothermal reaction temperature is 90-100℃, and the reaction time is 4-6h; mixing the precursor powder and SeO2, dispersing in N,N-dimethylformamide, and mixing and dispersing uniformly by ultrasonic, and then transferring the mixed solution to a Teflon reaction kettle, and reacting at 200-240℃ for 20-24h; after the reaction is completed, washing and drying the precipitate with deionized water and ethanol to obtain the bifunctional electrolytic water hydrogen production catalyst.

2. The production method according to claim 1, characterized by: The precursor powder and SeO2 are mixed, wherein the mass ratio of the precursor powder to SeO2 is 0.5g:1.5g.

3. The production method according to claim 1, wherein: The precursor powder and SeO2 are mixed and dispersed in N,N-dimethylformamide, wherein the ratio of the precursor powder to N,N-dimethylformamide is 0.5g:60mL.

4. The production method according to claim 1, wherein: The drying, wherein the drying temperature is 80℃, and the drying time is 24h.

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