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CN-121976234-A - Preparation method and application of urea electrocatalytic hydrogen production anode catalyst

CN121976234ACN 121976234 ACN121976234 ACN 121976234ACN-121976234-A

Abstract

A preparation method and application of an anode catalyst for hydrogen production by electrocatalytic urea relate to the technical field of preparation of anode catalysts for hydrogen production by electrolysis. The invention regulates and controls the electronic structure of the catalyst through the composite design of the nano structure and the nitrogen-containing conductive carbon material derived from chitosan, enhances the conductivity of the LDH material through the composite of graphitized amorphous carbon derived from chitosan and NiFe-LDH, inhibits the growth of nano sheets, enhances the specific surface area, increases the number of active sites, avoids the influence of the easy accumulation of the traditional LDH nano sheets on the exposure of the active sites in the process of the electro-catalytic urea, and has lower raw material cost and suitability for the large-scale industrial production of the electro-catalytic urea hydrogen production reaction of urea-assisted electrolytic water.

Inventors

  • ZHAO JIN
  • JIANG TIANXIANG
  • WANG XUNLIANG
  • MA YUHUI
  • CHENG YU
  • CAO JUNRUI

Assignees

  • 自然资源部天津海水淡化与综合利用研究所

Dates

Publication Date
20260505
Application Date
20260120

Claims (9)

  1. 1. The preparation method of the anode catalyst for the electrocatalytic hydrogen production of urea comprises the following steps of (1) pretreatment of foam nickel, (2) preparation of ferronickel salt solution containing chitosan, (3) preparation of the anode catalyst for the electrocatalytic hydrogen production of urea, wherein, (1) The pretreatment of the foam nickel comprises the steps of sequentially placing the first foam nickel into acetone, deionized water, hydrochloric acid solution and deionized water, respectively ultrasonically cleaning to remove organic matters and oxide layers on the surface of the foam nickel, and then vacuum drying to obtain second foam nickel, namely pretreated foam nickel; (2) Adding divalent nickel (Ni 2+ ) salt, trivalent iron (Fe 3+ ) salt and urea into deionized water respectively, uniformly stirring to form a uniform solution of divalent nickel salt, trivalent iron salt and urea, then adding a chitosan solution, and stirring to the uniform solution to obtain a chitosan-containing ferronickel salt solution; (3) The preparation method of the anode catalyst for the hydrogen production by the electro-catalytic urea comprises the steps of immersing second foam nickel into a nickel-iron salt solution containing chitosan for hydrothermal reaction, naturally cooling to room temperature after the reaction is finished, taking out the second foam nickel subjected to the hydrothermal reaction, respectively ultrasonically cleaning with absolute ethyl alcohol and deionized water, and then vacuum drying to obtain the anode catalyst for the hydrogen production by the electro-catalytic urea.
  2. 2. The preparation method of the urea electrocatalytic hydrogen production anode catalyst according to claim 1, wherein in the step (1), the molar concentration of the hydrochloric acid solution is 1-3 mol/L, the ultrasonic cleaning time is 2-10 min, the vacuum drying temperature is 60 ℃, and the vacuum drying time is 8-24 h; or, in the step (1), the molar concentration of the hydrochloric acid solution is 1-2 mol/L or 2-3 mol/L, the ultrasonic cleaning time is 2-6 min or 6-10 min, and the vacuum drying time is 8-16 h or 16-24 h.
  3. 3. The method for preparing the anode catalyst for the electrocatalytic hydrogen production from urea according to claim 1 or 2, wherein in the step (2), anions in the divalent nickel salt and anions in the trivalent iron salt are any one or a combination of at least two of sulfate, nitrate and chloride ions.
  4. 4. The method for preparing an anode catalyst for electrocatalytic hydrogen production from urea according to any one of claims 1 to 3, wherein the sum of the molar concentrations of the divalent nickel salt and the trivalent iron salt is 0.05 to 0.11mol/L, the molar ratio of the divalent nickel salt to the trivalent iron salt is (2 to 3): 1, the molar concentration of urea is 0.2 to 0.4mol/L, and the mass concentration of chitosan is 0.1 to 1.1g/L; Or, in the step (2), the sum of the molar concentration of the divalent nickel salt and the trivalent iron salt is 0.05-0.08 mol/L or 0.08-0.11 mol/L, the molar ratio of the divalent nickel salt to the trivalent iron salt is (2-2.5): 1 or (2.5-3): 1, the molar concentration of urea is 0.2-0.3 mol/L or 0.3-0.4 mol/L, and the mass concentration of chitosan is 0.1-0.6 g/L or 0.6-1.1 g/L.
  5. 5. The method for preparing the anode catalyst for the electrocatalytic hydrogen production from urea according to any one of claims 1 to 4, wherein the hydrothermal temperature of the hydrothermal reaction is 100 to 120 ℃ and the hydrothermal time is 6 to 12 hours in the step (3); Or, in the step (3), the hydrothermal temperature of the hydrothermal reaction is 100-110 ℃ or 110-120 ℃, and the hydrothermal time is 6-9 hours or 9-12 hours.
  6. 6. The method for preparing the anode catalyst for the electrocatalytic hydrogen production from urea according to any one of claims 1 to 5, wherein in the step (3), the ultrasonic cleaning time is 2 to 10min, the vacuum drying temperature is 60 ℃, and the vacuum drying time is 8 to 24h; Or, in the step (3), the ultrasonic cleaning time is 2-6 min or 6-10 min, and the vacuum drying time is 8-16 h or 16-24 h.
  7. 7. An anode catalyst for the electrocatalytic hydrogen production of urea obtained by a preparation method as claimed in any one of claims 1 to 6, wherein the catalyst is a nickel-iron double metal hydroxide having a laminate and an interlayer anion, the laminate is composed of nickel and iron hydroxides, and the interlayer anion is carbonate ion.
  8. 8. An anode catalyst for electrocatalytic hydrogen production from urea as set forth in claim 7, which is a nanostructured nickel-iron bimetallic hydroxide having a honeycomb morphology of laminate and interlayer anions.
  9. 9. Use of the urea electrocatalytic hydrogen production anode catalyst according to claim 7 or 8 in urea assisted water electrolysis hydrogen production reactions.

Description

Preparation method and application of urea electrocatalytic hydrogen production anode catalyst Technical Field The present disclosure relates to the technical field of preparation of anode catalysts for electrolytic hydrogen production, and in particular relates to a preparation method and application of a layered double hydroxide catalyst. Background The advantage of hydrogen gas with high energy density (about 142MJ kg -1) and zero carbon emissions is one of the most promising green energy sources. In many hydrogen production technologies such as fermentation hydrogen production, coal gasification and natural gas steam reforming, the electrolytic water hydrogen production is considered as a hydrogen production method with great potential due to environmental protection and sustainability, and importantly, electric energy can be generated by renewable energy systems such as wind energy, tidal energy and solar energy. In the electrolytic water hydrogen production system, the reaction consists of an Oxygen Evolution Reaction (OER) of an anode and a Hydrogen Evolution Reaction (HER) of a cathode, and the slow kinetics of the OER leads to serious hydrogen production power consumption, so that the development of a more ideal anode reaction to replace the OER reaction is a key for realizing the energy-saving hydrogen production technology. The theoretical potential (0.37V) of Urea Oxidation (UOR) is much lower than the thermodynamic potential (1.23V) of water electrolysis, and replacing OER as an anodic reaction is a viable method for effectively lowering the electrochemical barrier. Along with the gradual advancement of energy conservation and emission reduction policies, the electrocatalytic urea oxidation reaction can save energy and produce hydrogen, can purify urea-containing wastewater, and has important significance for realizing win-win effect of economy and environment. At present, noble metal-based catalysts such as ruthenium and iridium show stronger catalytic performance on OER and UOR, however, the problems of scarcity, high price and the like of noble metals limit the large-scale application of the noble metals, so that the non-noble metal UOR electrocatalyst with high catalytic activity and low cost is provided, and the non-noble metal UOR electrocatalyst is a technical problem to be solved in the current urea electrocatalytic hydrogen production field. Transition metal layered double hydroxides (TM-LDHs) are a focus of attention because of their unique layered structure, adjustable chemical composition, and layered structure. In particular, nickel-iron layered double hydroxide (NiFe-LDH) is typically represented as an LDH structure composed of a nano-scale metal hydroxide laminate with positively charged Ni and Fe and interlayer anions, and has the advantages of high catalytic activity, low cost, easiness in compounding with other materials and the like. CN 115249818B discloses a layered double hydroxide composite material, a preparation method and application thereof, wherein the preparation method comprises the steps of sequentially adding cobalt nitrate hexahydrate, nickel nitrate hexahydrate and urea into deionized water, immersing carbon cloth, carrying out hydrothermal reaction, then adding sodium hypophosphite to obtain NiCoP@CC, sequentially adding nickel nitrate hexahydrate, ferrous sulfate heptahydrate and urea into deionized water, immersing the obtained NiCoP@CC, and carrying out hydrothermal reaction to obtain the NiCoP/NiFe LDH@CC, namely the layered double hydroxide composite material. CN 120440986B discloses a nickel-iron layered double hydroxide with a flaky nano flower morphology, a preparation method and application thereof, wherein the preparation method comprises the steps of dissolving nickel acetate in an organic solvent or a mixed solvent of the organic solvent and water to prepare a first solution, dissolving ferrous salt in water to prepare a second solution, uniformly mixing the first solution and the second solution, and standing and aging to obtain the nickel-iron layered double hydroxide. In summary, the prior art or the preparation process of the composite material requiring multiple steps is unfavorable for large-scale production in a complex preparation process, and the prepared composite material generally has the problem of weak interfacial bonding force, so that the structural stability and catalytic durability of the catalyst in a severe urea oxidation reaction working condition can not be fundamentally ensured, or the catalyst is limited to the morphological modification from the physical level of the nanoflower, and the intrinsic conductivity and catalytic activity of the NiFe-LDH active site can not be improved from the electronic structure level. Therefore, the NiFe-LDH-based urea electrocatalytic hydrogen production anode catalyst which has strong conductivity, multiple active sites and strong stability and is simple and convenient in preparation method,