A ternary metal chalcogenide bifunctional water hydrogen production catalyst and a preparation method thereof

Abstract

The application discloses a ternary metal telluride bifunctional water hydrogen production catalyst and a preparation method. x (CoNi)‑MOF; and then the Fe x (CoNi)Te x is loaded on the foam nickel to obtain a catalyst material Fe x (CoNi)Te x (CoNi)Te x (CoNi)Te x@ NF, wherein Fe2(CoNi)Te @ NF has excellent HER and OER catalytic activity, has rich active sites, and has excellent characteristics such as low overpotential, excellent kinetics, small impedance and good cycle stability. The application provides a high-efficiency non-noble metal catalyst with low cost and excellent catalytic activity for water electrolysis hydrogen production, and can effectively promote the commercialization process of hydrogen production technology.

Description

TECHNICAL FIELD

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

[0002] The increasing energy demand and the gradual deterioration of the environment caused by fossil fuel consumption have stimulated the development of renewable energy such as solar energy, wind energy and hydrogen energy. Among them, hydrogen energy, which is efficient, environmentally friendly and sustainable, is the most promising candidate energy. Energy storage through water splitting into hydrogen molecules relies on the hydrogen evolution reaction, but due to the slow kinetics and high energy barrier of the cathode hydrogen evolution reaction and the anode oxygen evolution reaction in the process of electrocatalytic water splitting, 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 noble metals have excellent electrocatalytic performance, they have the disadvantages of high catalyst cost, limited resources and poor stability, which restricts their large-scale commercial production. Therefore, the development of non-noble metal catalysts is crucial for the development of water electrolysis hydrogen production technology. SUMMARY

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

[0005] The embodiment of the application discloses a ternary metal telluride bifunctional water hydrogen production catalyst, wherein the catalyst is prepared by calcining Fe x (CoNi)Te x (CoNi)Te x (CoNi)Te x @NF catalyst material.

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

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

[0008] S1 dissolve iron nitrate nonahydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate and fumaric acid in N,N-dimethylformamide according to a specific ratio to synthesize Fe x (CoNi)-MOF by one-step hydrothermal method.

[0009] S2 will use the Fe obtained in step S1 x (CoNi)-MOF and tellurium powder are calcined at high temperature in a H2 / Ar mixed gas for a certain period of time in a certain proportion to obtain Fe. x (CoNi)Te x ;

[0010] S3 uses the Fe obtained in step S2. x (CoNi)Te x Dissolved in a mixed solution of 5 wt% naphthol, anhydrous ethanol and deionized water, and sonicated for 60 min to obtain a uniformly dispersed sample solution.

[0011] S4 First, process 1cm*2cm nickel foam for later use;

[0012] The sample solution obtained in S3 was pipetted onto a 1cm x 1cm section of nickel foam at a frequency of 20 μL / drop, with a 5-minute interval between each drop. This operation was repeated until the solution was completely added. The foam was then placed in an oven to dry, yielding 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 to 1.2, and the calcination regime is: calcination at 500℃ for 10h, with a heating rate of 3℃ / min.

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

[0016] The advantages of this invention are: (1) Fe obtained through synthesis 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 is inexpensive, providing a cost-effective and highly efficient non-precious metal catalyst for hydrogen production by water electrolysis. (2) The tellurization process significantly enhances the Fe xThe reaction kinetics of the (CoNi)Te material improves the charge density, reduces the distance from the d-band to the Fermi level, thereby promoting the separation of carriers, providing more abundant electrochemically 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 to promote the commercialization process of electrocatalytic hydrogen production. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings described below are only some embodiments described in the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

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

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

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

[0021] The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0022] Example 1

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

[0024] Iron nitrate nonahydrate is Fe(N03)3-9H20, cobalt nitrate hexahydrate is Co(N03)2-6H20, nickel nitrate hexahydrate is Ni(N03)2-6H20, and N,N-dimethylformamide solution is DMF solution.

[0025] 2.5 mmol of Fe(N03)3-9H20, 1.25 mmol of Co(N03)2-6H20, 1.25 mmol of Ni(N03)2-6H20, and 40 mmol of fumaric acid were dissolved in 50 ml of DMF solution, and stirred at a rotation speed of 200 rpm at room temperature for 30 min.

[0026] The above obtained solution was transferred to a reaction kettle, and then placed in a 120°C oven for reaction for 8 h. After centrifugation at a rotation speed of 3000 rpm for 3 min, it was washed with deionized water and ethanol for multiple times, and placed in a 40°C oven for drying for 8 h to collect Fe2(CoNi)-MOF.

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

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

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

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

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

[0032] The above obtained solution was dropped on a 1 cm*1 cm position of the treated foam nickel using a pipette at a frequency of 20 μΐ per time, and the time interval for each drop was 5 min. This operation was repeated until the solution was dropped completely. The sample was dried in a 40°C oven for 1 h to obtain Fe2(CoNi)Te@NF.

[0033] Example 2

[0034] The mass ratio of Fe2(CoNi)MOF and tellurium powder in step (2) was changed to 1:0.8, and finally Fe2(CoNi)Te was obtained 0.8 ; 2 mg of Fe2(CoNi)Te was weighed in step (3) 0.8 , and Fe2(CoNi)Te was obtained 0.8 @NF, the rest remained unchanged.

[0035] Example 3

[0036] The mass ratio of Fe2(CoNi)MOF and tellurium powder in step (2) was changed to 1:1.2, and finally Fe2(CoNi)Te was obtained 1.2 ; 2 mg of Fe2(CoNi)Te was weighed in step (3) 1.2 , and Fe2(CoNi)Te was obtained 1.2 @NF, the rest remained unchanged.

[0037] Example 4

[0038] Step (2) was removed, and Fe2(CoNi)MOF was changed to Fe2(CoNi)Te in step (3), and finally Fe2(CoNi)-MOF@NF was obtained.

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

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

[0041] The OER electrochemical performance is shown in Figure 2The Fe2(CoNi)-MOF@NF and Fe2(CoNi)Te shown x @NF has a lower overpotential than the commercial catalyst RuO2. Figure 2 a), and the reaction kinetics are 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 increases by only 16mV at the current density. Figure 2 d) After a 30-hour cycle stability test, its performance still remained at 93.01% of its original value. Figure 2 d). The above results demonstrate that Fe2(CoNi)Te@NF exhibits excellent HER and OER catalytic performance and excellent cycle stability.

[0042] Next, the overall water splitting performance of the catalysts prepared in Examples 1-4 was tested, and the overall water splitting performance was as follows: Figure 3 As shown, at 10mAcm -2 and 100mA cm -2 At current densities, both Fe2(CoNi)-MOF@NF and Fe2(CoNi)Te@NF exhibit lower threshold potentials than the commercial catalyst Pt / C|RuO2, and at 10 mA / cm², they show even lower threshold potentials. -2 At the specified current density, after 30 hours of cycling stability testing, Fe2(CoNi)Te@NF maintained 88.23% of its original performance. These results demonstrate that both Fe2(CoNi)-MOF@NF and Fe2(CoNi)Te@NF exhibit excellent water-splitting performance, with Fe2(CoNi)Te@NF showing superior water-splitting performance and excellent cycling stability.

[0043] This embodiment is merely an illustrative description of the present patent and does not limit its scope of protection. Those skilled in the art may make partial modifications to it. As long as they do not exceed the spirit and essence of the present patent, they shall be regarded as equivalent substitutions to the present patent and shall be within the scope of protection of the present patent.

Claims

1. A method for preparing ternary metal chalcogenide bifunctional water electrolysis hydrogen evolution catalyst, characterized in that, The method comprises the following steps: S1 Iron nitrate nonahydrate, cobalt nitrate hexahydrate, nickel nitrate hexahydrate and fumaric acid were dissolved in N,N-dimethylformamide in a molar ratio of 2:1:1:32~40, and Fe x (CoNi)-MOF; S2 Fe obtained in S1 step is dissolved in HCl solution x (CoNi)-MOF and tellurium powder are calcined in H2 / Ar mixed gas at a certain ratio for a certain time to obtain Fe x (CoNi)Te x ; S3 Fe prepared in S2 step was dissolved in a mixed solution consisting of 5 wt% naphthol, anhydrous ethanol and deionized water, and a uniformly dispersed sample solution was obtained after ultrasonic treatment for 60 min. x (CoNi)Te x S3 Fe prepared in S2 step was dissolved in a mixed solution consisting of 5 wt% naphthol, anhydrous ethanol and deionized water, and a uniformly dispersed sample solution was obtained after ultrasonic treatment for 60 min. S4 first 1 cm*2 cm foam nickel treatment for standby; again, the sample solution obtained from S3 is dropped on the 1 cm*1 cm position of the foam nickel using a pipette at a frequency of 20 μL / time, and the time interval for each drop is 5 min. This operation is repeated until the solution is dropped, and then it is placed in an oven for drying to obtain Fe x (CoNi)Te x @NF; Wherein, the Fe x (CoNi)Te x Specifically Fe2(CoNi)Te 0.8~1.2 .

2. A method for preparing a ternary metal chalcogenide bifunctional water electrolysis hydrogen evolution catalyst according to claim 1, characterized in that, Fe2(CoNi)Te 0.8~1.2 Fe2(CoNi)Te.

3. A method of preparing a ternary metal chalcogenide bifunctional water electrolysis hydrogen evolution catalyst according to claim 1, characterized in that, The calcination system in the step S2 is: calcination at 500 DEG C for 10h, and the heating rate is 3 DEG C / min.

4. The preparation method of a ternary metal telluride bifunctional hydroelectric hydrogen production catalyst as described in claim 1, characterized in that, The ratio of 5 wt% naphthol, anhydrous ethanol and deionized water in the step S3 is 1:10:5.

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