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CN-115572988-B - Preparation method of CoMoP/FeCoS/NF composite catalyst for full-pH electrolysis of water to produce hydrogen

CN115572988BCN 115572988 BCN115572988 BCN 115572988BCN-115572988-B

Abstract

The invention discloses a preparation method of a CoMoP/FeCoS/NF composite catalyst for preparing hydrogen by full-pH electrolysis water, belonging to the technical field of new energy materials. The invention aims to solve the problems that the existing noble metal catalyst has high cost, but the non-noble metal catalyst is only suitable for an alkaline electrolytic tank and has limited reaction activity under the condition of acidic or neutral medium. The method comprises the steps of preparing FeCoS/NF precursor and preparing CoMoP/FeCoS/NF composite catalyst. The method is used for preparing the CoMoP/FeCoS/NF composite catalyst for preparing hydrogen by full-pH electrolysis water.

Inventors

  • CAI XIAODONG
  • SONG QUN
  • JIAO DANHUA
  • YU HUATONG
  • LU WENJUAN

Assignees

  • 贵州民族大学

Dates

Publication Date
20260505
Application Date
20221020

Claims (10)

  1. 1. The preparation method of the CoMoP/FeCoS/NF composite catalyst for preparing hydrogen by full-pH electrolysis water is characterized by comprising the following steps: 1. preparation of FeCoS/NF precursor: uniformly dispersing a cobalt source, an iron source and a sulfur source in ethylene glycol, performing ultrasonic treatment to obtain a uniform and stable mixed solution A, immersing foam nickel in the uniform and stable mixed solution A, reacting for 8-12 h at 150-240 ℃, and finally washing and drying to obtain FeCoS/NF precursor; 2. preparation of CoMoP/FeCoS/NF composite catalyst: Uniformly dispersing cobalt nitrate hexahydrate, sodium hypophosphite, sodium molybdate and trisodium citrate in deionized water, stirring to obtain uniform and stable mixed solution B, taking the uniform and stable mixed solution B as electrolyte, feCoS/NF precursor as a working electrode, a carbon rod as a counter electrode and Ag/AgCl as a reference electrode, and depositing 60 s-150 s under the condition of constant voltage to obtain the CoMoP/FeCoS/NF composite catalyst.
  2. 2. The method for preparing the hydrogen CoMoP/FeCoS/NF composite catalyst for full-pH electrolysis of water, which is disclosed in claim 1, is characterized in that cobalt source in the first step is cobalt chloride hexahydrate, iron source in the first step is ferrous sulfate heptahydrate, and sulfur source in the first step is thiourea.
  3. 3. The preparation method of the CoMoP/FeCoS/NF composite catalyst for full-pH electrolysis of water to produce hydrogen is characterized in that the molar ratio of a cobalt source to an iron source in the step I is 1 (0.5-2), the molar ratio of the cobalt source to a sulfur source in the step I is 1 (1-3), and the volume ratio of the cobalt source to ethylene glycol in the step I is 1mmol (20-50) mL.
  4. 4. The method for preparing the hydrogen CoMoP/FeCoS/NF composite catalyst for full-pH electrolysis of water, which is characterized in that the ultrasonic treatment in the first step is specifically carried out under the condition of 200-500W of power for 0.5-2 h.
  5. 5. The preparation method of the CoMoP/FeCoS/NF composite catalyst for full-pH electrolytic water production is characterized in that the foam nickel in the first step is the foam nickel after pretreatment, the pretreatment is specifically carried out according to the following steps that ① is sequentially washed with hydrochloric acid, acetone, ethanol and ultrapure water with the concentration of 2 mol/L-4 mol/L in an ultrasonic mode, ② is repeated for ① times to 4 times, and finally the foam nickel is dried for 6 hours to 10 hours at the temperature of 50 ℃ to 60 ℃.
  6. 6. The method for preparing the hydrogen CoMoP/FeCoS/NF composite catalyst for full-pH electrolysis of water according to claim 1, wherein the washing and drying in the first step is specifically washing with deionized water, and then drying for 8-12 h under the condition that the temperature is 50-60 ℃.
  7. 7. The method for preparing the hydrogen production CoMoP/FeCoS/NF composite catalyst for full-pH electrolysis of water, which is characterized in that the purity of the foam nickel in the step one is 99.99%, the thickness is 1 mm-2 mm, and the pore diameter is 100 PPI-120 PPI.
  8. 8. The preparation method of the CoMoP/FeCoS/NF composite catalyst for full-pH electrolytic water production according to claim 1 is characterized in that the mass ratio of cobalt nitrate hexahydrate to sodium hypophosphite in the second step is 1 (3-4), the mass ratio of cobalt nitrate hexahydrate to sodium molybdate in the second step is 1 (0.5-1.5), the mass ratio of cobalt nitrate hexahydrate to trisodium citrate in the second step is 1 (0.5-1), and the volume ratio of cobalt nitrate hexahydrate to deionized water in the second step is 1g (700-1000) mL.
  9. 9. The method for preparing the hydrogen CoMoP/FeCoS/NF composite catalyst for full-pH electrolysis of water, which is characterized in that stirring in the second step is carried out for 0.5-1.5 h under the condition that the rotating speed is 200-500 r/min.
  10. 10. The preparation method of the CoMoP/FeCoS/NF composite catalyst for full-pH electrolysis of water to produce hydrogen according to claim 1, which is characterized in that 60 s-150 s is deposited under the condition that constant voltage is-0.5V to-3V in the second step.

Description

Preparation method of CoMoP/FeCoS/NF composite catalyst for full-pH electrolysis of water to produce hydrogen Technical Field The invention belongs to the technical field of new energy materials. Background The excessive consumption of non-renewable energy sources and the consequent environmental pollution problems have forced us to find and develop renewable clean energy sources, where hydrogen energy is considered one of the most promising clean energy sources in the 21 st century. Electrolytic water hydrogen production (HER) is considered to be a clean production technology that is environmentally friendly, highly selective and does not produce secondary pollution. However, the process of water decomposition belongs to non-spontaneous reaction from the chemical thermodynamic point of view, and the reaction rate is slow, and the water decomposition can be realized only by overcoming a certain activation potential energy with the aid of a catalyst, so that the development of an efficient water electrolysis catalyst is urgent. At present, the high-efficiency electrocatalyst is still mainly made of rare and expensive noble metal-based materials, which is not beneficial to the large-scale popularization of the hydrogen production by water electrolysis in industry. And most of the reported non-noble metal catalysts are only suitable for alkaline electrolytic cells, and have very limited reactivity under the condition of acidic or neutral medium, but in the practical application process, the electrolytic water hydrogen production technology has various requirements on the pH of electrolyte solution. Therefore, development of an efficient, stable, low-overpotential and low-cost full-pH hydrogen evolution electrocatalyst is imperative. Disclosure of Invention The invention aims to solve the problems that the existing noble metal catalyst has high cost, but the non-noble metal catalyst is only suitable for an alkaline electrolytic tank and has limited reaction activity under the condition of acidic or neutral medium, and provides a preparation method of the CoMoP/FeCoS/NF composite catalyst for full-pH electrolysis of water to produce hydrogen. The preparation method of the CoMoP/FeCoS/NF composite catalyst for preparing hydrogen by full-pH electrolysis water is carried out according to the following steps: 1. preparation of FeCoS/NF precursor: uniformly dispersing a cobalt source, an iron source and a sulfur source in ethylene glycol, performing ultrasonic treatment to obtain a uniform and stable mixed solution A, immersing foam nickel in the uniform and stable mixed solution A, reacting for 8-12 h at 150-240 ℃, and finally washing and drying to obtain FeCoS/NF precursor; 2. preparation of CoMoP/FeCoS/NF composite catalyst: Uniformly dispersing cobalt nitrate hexahydrate, sodium hypophosphite, sodium molybdate and trisodium citrate in deionized water, stirring to obtain uniform and stable mixed solution B, taking the uniform and stable mixed solution B as electrolyte, feCoS/NF precursor as a working electrode, a carbon rod as a counter electrode and Ag/AgCl as a reference electrode, and depositing 60 s-150 s under the condition of constant voltage to obtain the CoMoP/FeCoS/NF composite catalyst. The invention has the beneficial effects that the invention discloses the preparation of the CoMoP/FeCoS/NF composite catalyst for producing hydrogen by full-pH electrolysis water. The overpotential obtained by testing the catalyst in alkaline, neutral and acid environments under the condition of the current density of 10mA/cm 2 is 104mV, 171mV and 27mV respectively, and the catalyst shows excellent full pH electrolyzed water performance and can keep stability not lower than 20 h. The CoMoP/FeCoS/NF composite catalyst prepared by the invention has the advantages of simple preparation method, low cost, catalytic performance comparable to that of commercial noble metal catalysts, and good application prospect in the aspect of hydrogen production by water electrolysis. The invention is used for preparing a CoMoP/FeCoS/NF composite catalyst for preparing hydrogen by full-pH electrolysis water. Drawings FIG. 1 is an X-ray diffraction pattern (XRD), 1 is a CoMoP/FeCoS/NF composite catalyst prepared in example one, 2 is a FeCoS/NF catalyst prepared in comparative experiment one, and 3 is a NF catalyst prepared in comparative experiment three; FIG. 2 is an X-ray photoelectron diffraction Spectrometry (XPS) of the CoMoP/FeCoS/NF composite catalyst prepared in example one; FIG. 3 is a Scanning Electron Microscope (SEM), (a) is FeCoS/NF catalyst prepared in comparative experiment one, and (b) is CoMoP/FeCoS/NF composite catalyst prepared in example one; FIG. 4 is a Transmission Electron Microscope (TEM) of the CoMoP/FeCoS/NF composite catalyst prepared in example one, (a) is a scale of 500nm, (b) is a partial enlarged view of (a), (c) is a scale of 5nm, and (d) is a partial enlarged view of (c); FIG. 5 is a graph of HER linear sweep