Ternary metal telluride difunctional catalyst for hydrogen production from water and preparation method of ternary metal telluride difunctional catalyst

Abstract

The invention discloses a ternary metal telluride bifunctional catalyst for hydrogen production from water and a preparation method thereof.The preparation method comprises the specific steps that ferric nitrate nonahydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate and fumaric acid serve as raw materials, the raw materials are stirred to be uniform in N, N-dimethylformamide, and Fex (CoNi)-MOF is obtained through reaction under specific conditions of a reaction kettle, centrifugation, cleaning and drying; then carrying out high-temperature calcination on the Fex (CoNi) Tex and tellurium powder according to a specific ratio in H2 / Ar mixed gas to prepare Fex (CoNi) Tex; fex (CoNi) Tex is loaded on foamed nickel, the catalyst material Fex (CoNi) Te (at) NF is prepared, and Fe2 (CoNi) Te (at) NF has excellent HER and OER catalytic activity, has rich active sites and has the excellent characteristics of low overpotential, excellent dynamics, small impedance, good cycling stability and the like. The efficient non-noble metal catalyst which is low in cost and excellent in catalytic activity is provided for hydrogen production through water electrolysis, and the commercialization process of the hydrogen production technology can be powerfully promoted.

Description

Technical Field

[0001] The present application relates to the technical field of catalyst preparation, and in particular to a ternary metal telluride bifunctional water hydrogen production catalyst and a preparation method thereof. Background Art

[0002] The increase in energy demand and the worsening environmental problems caused by fossil fuel consumption have stimulated the development of renewable energy sources such as solar energy, wind energy, and hydrogen energy. Among them, efficient, environmentally friendly, and sustainable hydrogen energy is the most promising candidate energy source. Storing energy by splitting water into hydrogen molecules relies on the hydrogen evolution reaction. However, due to the slow kinetics and high energy barriers of the cathode hydrogen evolution reaction and the anode oxygen evolution reaction in the electrocatalytic water splitting process, it is very important to design efficient catalysts to reduce the activation energy of the reaction for the production of clean energy.

[0003] Although iridium and ruthenium oxides based on precious metals have excellent electrocatalytic properties, they have disadvantages such as high catalyst cost, limited resources, and poor stability, which restrict their large-scale commercial production. Therefore, the development of non-precious metal catalysts is crucial to promoting the development of water electrolysis hydrogen production technology. Summary of the invention

[0004] The purpose of this application is to provide a ternary metal telluride catalyst that can significantly reduce the energy barrier of water electrolysis reaction, improve the hydrogen production efficiency by reducing the activation energy of catalytic water electrolysis reaction, have excellent HER and OER catalytic activity, promote the development of water electrolysis hydrogen production technology, and thus solve the problems of increased energy demand and environmental degradation caused by the large-scale use of traditional fossil fuels.

[0005] The present application discloses a ternary metal telluride bifunctional water hydrogen production catalyst, wherein the catalyst is prepared by calcining an iron-cobalt-nickel three-element metal-organic framework and tellurium powder to form Fe x (CoNi)Te x , and then loaded on nickel foam to prepare Fe x (CoNi)Te x @NF catalyst material.

[0006] Preferably, the catalyst material is Fe2(CoNi)Te 0.8～1.2 , preferably Fe2(CoNi)Te.

[0007] The present application also discloses a method for preparing a ternary metal telluride bifunctional water hydrogen production catalyst, and the specific preparation steps are as follows:

[0008] S1: Ferric nitrate nonahydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate and fumaric acid were dissolved in N,N-dimethylformamide in a specific ratio and Fe was synthesized by a one-step hydrothermal method. x (CoNi)-MOF;

[0009] S2: Fe obtained in step S1 x (CoNi)-MOF and tellurium powder were calcined in a H2 / Ar mixed gas at a certain ratio for a certain period of time to obtain Fe x (CoNi)Te x ;

[0010] S3: Fe x (CoNi)Te x The sample was dissolved in a mixed solution consisting of 5 wt% naphthol, anhydrous ethanol and deionized water, and then ultrasonicated for 60 min to obtain a uniformly dispersed sample solution;

[0011] S4 first treats 1cm*2cm nickel foam for later use;

[0012] The sample solution obtained in S3 was dripped onto the 1cm*1cm position of the nickel foam at a frequency of 20 μL / time using a pipette, and the time interval between each dripping was 5 min. This operation was repeated until the solution was dripped and placed in an oven to dry to obtain Fe x (CoNi)Te x @NF.

[0013] Preferably, the molar mass ratio of ferric nitrate nonahydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate, and fumaric acid in step S1 is 2:1:1:32-40.

[0014] Preferably, in step S2, Fe x The mass ratio of (CoNi)MOF to tellurium powder is 1:0.8-1.2, and the calcination system is: calcination at 500°C for 10h, with a heating rate of 3°C / min.

[0015] Preferably, in step S3, the ratio of 5 wt% naphthol, anhydrous ethanol and deionized water is 1:10:5.

[0016] The advantages of the present invention are: (1) the Fe x (CoNi)Te x @NF, especially Fe2(CoNi)Te@NF, as a bifunctional electrocatalyst for HER and OER, has excellent HER and OER catalytic activity and low cost, providing a low-cost, high-efficiency non-precious metal catalyst for hydrogen production by water electrolysis. (2) The tellurization process significantly enhances the Fe xThe reaction kinetics of (CoNi)Te materials increases the charge density and reduces the distance from the d-band to the Fermi level, thereby promoting the separation of carriers, providing more abundant electrochemical active sites, and effectively improving the electrocatalytic efficiency. (3) The prepared Fe2(CoNi)Te METe has excellent HER and OER stability in long-term water splitting reactions, can be used for a long time, has high practical application value, and helps promote the commercialization of electrocatalytic hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 The Fe2(CoNi)-MOF@NF and Fe2(CoNi)Te obtained in Examples 1-4 are shown. x HER electrochemical performance results of @NF and commercial catalyst Pt / C; in the figure: (a) linear scan curve (LSV), (b) Tafel slope (Tafel), (c) electrochemical impedance spectroscopy (EIS) and (d) cycle stability curve (it).

[0019] Figure 2 The Fe2(CoNi)-MOF@NF and Fe2(CoNi)Te obtained in Examples 1-4 are shown. x OER electrochemical performance results of @NF and commercial catalyst RuO2; in the figure: (a) linear scan curve (LSV), (b) Tafel slope (Tafel), (c) electrochemical impedance spectroscopy (EIS) and (d) cycle stability curve (it).

[0020] Figure 3 Linear scanning curves (LSV) of Fe2(CoNi)-MOF@NF, Fe2(CoNi)Te@NF and commercial catalyst Pt / C|RuO2 in Examples 1 and 4. DETAILED DESCRIPTION

[0021] The following will describe the technical solutions in the embodiments of the present invention in detail in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Example 1

[0023] (1) Preparation of Fe2(CoNi)-MOF materials

[0024] Iron nitrate nonahydrate is Fe(NO3)3·9H2O, cobalt nitrate hexahydrate is Co(NO3)2·6H2O, nickel nitrate hexahydrate is Ni(NO3)2·6H2O, and N,N-dimethylformamide solution is DMF solution.

[0025] Dissolve 2.5 mmol of Fe(NO3)3·9H2O, 1.25 mmol of Co(NO3)2·6H2O, 1.25 mmol of Ni(NO3)2·6H2O and 40 mmol of fumaric acid in 50 ml of DMF solution and stir at room temperature at 200 rpm for 30 min.

[0026] The solution obtained above was transferred to a reactor, and then placed in an oven at 120°C for reaction for 8 hours. After centrifugation at 3000 rpm for 3 minutes, it was washed with deionized water and ethanol for multiple times, and placed in an oven at 40°C for drying for 8 hours to obtain Fe2(CoNi)-MOF.

[0027] (2) Preparation of Fe2(CoNi)Te

[0028] Fe2(CoNi)MOF and tellurium powder were mixed evenly in a mass ratio of 1:1, and then the temperature was raised to 500°C at 3°C / min in a tube furnace and calcined in a H2 / Ar atmosphere for 10 h to obtain Fe2(CoNi)Te.

[0029] (3) Preparation of Fe2(CoNi)Te@NF

[0030] 2 mg of Fe2(CoNi)Te was weighed and dissolved in a mixed solution consisting of 20 μL of naphthol (5 wt.%), 200 μL of anhydrous ethanol and 100 μL of deionized water. The mixture was ultrasonicated for 60 min to obtain a uniformly dispersed sample solution.

[0031] The nickel foam with a size of 1cm*2cm was ultrasonically cleaned with 1mmol / L HCL, 1mmol / LNaOH, acetone, deionized water and anhydrous ethanol for 1h respectively, and then dried in a vacuum oven at 50°C for 2h.

[0032] The solution obtained above was dripped onto a 1cm*1cm position of the treated nickel foam at a frequency of 20 μL / time using a pipette, with an interval of 5 minutes between each dripping. This operation was repeated until the solution was dripped off, and the sample was dried in an oven at 40°C for 1 hour to obtain Fe2(CoNi)Te@NF.

[0033] Example 2

[0034] In step (2), the mass ratio of Fe2(CoNi)MOF and tellurium powder was changed to 1:0.8, and finally Fe2(CoNi)Te 0.8 ; In step (3), weigh 2 mg of Fe2(CoNi)Te 0.8 , Fe2(CoNi)Te 0.8 Except @NF, the rest remain unchanged.

[0035] Example 3

[0036] In step (2), the mass ratio of Fe2(CoNi)MOF and tellurium powder was changed to 1:1.2, and finally Fe2(CoNi)Te 1.2 ; In step (3), weigh 2 mg of Fe2(CoNi)Te 1.2 , Fe2(CoNi)Te 1.2 Except @NF, the rest remain unchanged.

[0037] Example 4

[0038] Step (2) was removed and Fe2(CoNi)Te in step (3) was replaced with Fe2(CoNi)MOF to finally obtain Fe2(CoNi)-MOF@NF.

[0039] Electrochemical performance tests were performed on Examples 1-4: Fe2(CoNi)-MOF@NF and Fe2(CoNi)Te x @NF is the working electrode, saturated Ag / AgCl (1MKOH) is the reference electrode, and carbon rod (HER) / platinum sheet (OER) is the counter electrode.

[0040] HER electrochemical performance Figure 1 As shown in Figure 2, Fe2(CoNi)-MOF@NF and Fe2(CoNi)Te@NF have lower overpotentials than the commercial catalyst Pt / C ( Figure 1 a), and the reaction kinetics were significantly enhanced ( Figure 1 b), and Fe2(CoNi)Te@NF has a smaller impedance ( Figure 1 c), after 2000 cycles, at 200mAcm -2 The voltage only increased by 18mV at a current density of Figure 1 d), after 30h of cycle stability test, its performance can still be maintained at 89.93% of the original ( Figure 1 d).

[0041] OER electrochemical performance Figure 2Fe2(CoNi)-MOF@NF and Fe2(CoNi)Te x @NF has a lower overpotential than the commercial catalyst RuO2 ( Figure 2 a), and the reaction kinetics were significantly enhanced ( Figure 2 b), and Fe2(CoNi)Te@NF has a smaller impedance ( Figure 2 c) After 2000 cycles, at 200 mA cm -2 The voltage only increased by 16mV at a current density of Figure 2 d), after 30h of cycle stability test, its performance can still maintain 93.01% of the original ( Figure 2 d). The above results demonstrate that Fe2(CoNi)Te@NF has excellent HER and OER catalytic performance and exhibits excellent cycling stability.

[0042] Next, the water splitting performance of the catalysts prepared in Examples 1-4 was tested. Figure 3 As shown, at 10mAcm -2 and 100mA cm -2 Both Fe2(CoNi)-MOF@NF and Fe2(CoNi)Te@NF have lower threshold potentials than commercial catalysts Pt / C|RuO2 at current densities of 10 mA cm -2 Under the current density, after 30h of cycle stability test, the performance of Fe2(CoNi)Te@NF can still be maintained at 88.23% of the original. The above results prove that both Fe2(CoNi)-MOF@NF and Fe2(CoNi)Te@NF have excellent overall water splitting performance, among which Fe2(CoNi)Te@NF material has better overall water splitting performance and shows excellent cycle stability.

[0043] This implementation mode is only an exemplary description of this patent and does not limit its protection scope. Personnel in this field may also make partial changes to it. As long as it does not exceed the spirit of this patent, it shall be regarded as an equivalent replacement of this patent and shall be within the protection scope of this patent.

Claims

1. A ternary metal telluride bifunctional water hydrogen production catalyst, wherein the catalyst is prepared by calcining an iron-cobalt-nickel three-element metal-organic framework and tellurium powder to form Fe x (CoNi)Te x , and then loaded on nickel foam to prepare Fe x (CoNi)Te x @NF catalyst material.

2. The catalyst according to claim 1, wherein the catalyst material is Fe2(CoNi)Te 0.8~1.2 , preferably Fe2(CoNi)Te.

3. The method for preparing the catalyst according to claim 1, characterized in that: The steps include: S1 Ferric nitrate nonahydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate and fumaric acid were dissolved in N,N-dimethylformamide in a specific ratio and Fe was synthesized by a one-step hydrothermal method. x (CoNi)-MOF; S2: Fe obtained in step S1 x (CoNi)-MOF and tellurium powder were calcined in a H2 / Ar mixed gas at a certain ratio for a certain period of time to obtain Fe x (CoNi)Te x ; S3: Fe x (CoNi)Te x Dissolved in a mixed solution consisting of 5 wt% naphthol, anhydrous ethanol and deionized water, and ultrasonicated for 60 min to obtain a uniformly dispersed sample solution; S4 first treats 1cm*2cm nickel foam for later use; The sample solution obtained in S3 was dripped onto the 1cm*1cm position of the nickel foam at a frequency of 20mL / time using a pipette, and the time interval between each dripping was 5min. This operation was repeated until the solution was dripped and placed in an oven to dry to obtain Fe x (CoNi)Te x @NF.

4. The preparation method according to claim 3, characterized in that: The molar mass ratio of the ferric nitrate nonahydrate, the cobalt nitrate hexahydrate, the nickel nitrate hexahydrate, and the fumaric acid in step S1 is 2:1:1:32-40.

5. The preparation method according to claim 3, characterized in that: In step S2, Fe x The mass ratio of (CoNi) MOF to tellurium powder is 1:0.8~1.2, and the calcination system is: calcination at 500°C for 10h, with a heating rate of 3°C / min.

6. The preparation method according to claim 3, characterized in that: In step S3, the ratio of 5 wt% naphthol, anhydrous ethanol and deionized water is 1:10:5.

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