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CN-122013234-A - Anti-poisoning electrocatalytic ammoxidation catalyst based on bimetallic-polyoxometallate interface and preparation method thereof

CN122013234ACN 122013234 ACN122013234 ACN 122013234ACN-122013234-A

Abstract

The invention relates to the technical field of electrocatalytic materials, and mainly discloses an anti-poisoning electrocatalytic ammoxidation catalyst based on a bimetal-polyoxometallate interface and a preparation method thereof. In the bimetal-POM structure constructed by the invention, the phosphotungstic acid anion skeleton provides a stable oxygen bridge coordination environment, cu and Ni active centers can be anchored on an atomic scale to prevent aggregation and dissolution under high potential, heterogeneous bimetal sites formed by Cu and Ni in the POM skeleton can realize electronic coupling regulation and control through an oxygen bridge, and the bimetallic-POM interface electronic regulation and control is realized.

Inventors

  • PENG MIN
  • HU WEI
  • DU HEBAO
  • PENG LIXIONG
  • ZHAO YUXUAN
  • ZHAO XI
  • HE WEI

Assignees

  • 上海澳思净科技有限公司

Dates

Publication Date
20260512
Application Date
20251230

Claims (10)

  1. 1. An anti-poisoning electrocatalytic ammoxidation catalyst based on a bimetal-polyoxometallate interface is characterized in that the catalyst is a composite material formed by in-situ growth on a pretreated nickel foam substrate through a hydrothermal method; the composite material comprises nickel ions provided by the dissolution of the nickel foam, exogenously introduced copper ions and complete Keggin type polyoxometallate anions, wherein the nickel ions and the copper ions form a stable bi-metal-polyoxometallate interface structure through bridging oxygen atoms in a polyoxometallate anion skeleton, and the bi-metal-polyoxometallate interface structure is used for synergistically catalyzing ammoxidation reaction under alkaline conditions to generate nitrate.
  2. 2. The anti-poisoning electrocatalytic ammonia oxidation catalyst based on a bi-metal-polyoxometallate interface as set forth in claim 1, wherein the molar ratio of nickel ions to copper ions is 1:1.
  3. 3. The anti-poisoning electrocatalytic ammoxidation catalyst based on a bi-metal-polyoxometallate interface of claim 2, wherein the polyoxometallate anion is selected from the group consisting of phosphotungstic acid radical anions ) Phosphate radical anion [ ] ) Silicotungstic acid radical anion [ ] ) Or silicomolybdate anions ) At least one of them.
  4. 4. A method for preparing an anti-poisoning electrocatalytic ammoxidation catalyst based on a bimetallic-polyoxometallate interface as set forth in claim 1, comprising the steps of: S1, pretreatment of a carrier, namely sequentially placing commercial nickel foam with the size of 1 cm multiplied by 4 cm into 3 mol/L hydrochloric acid solution, acetone, deionized water and absolute ethyl alcohol for ultrasonic cleaning, and soaking each solvent for 20 min; s2, preparing precursor solution, reacting and assembling, and weighing 1 mmol nickel nitrate hexahydrate @ the precursor solution ) And 1 mmol sodium dodecyl phosphate ) Dissolving in 40 mL deionized water, magnetically stirring to form a light green transparent solution, completely immersing the nickel foam pretreated in the step S1 into the solution, and sealing in a 50 mL polytetrafluoroethylene lining reaction kettle; S3, performing hydrothermal reaction to generate a Ni-PTA (Cu) compound, heating the reaction kettle in the S2 to 180 ℃ and preserving heat for 8 h; S4, washing and drying the sample, naturally cooling to room temperature after the reaction is finished, taking out the sample, alternately ultrasonically washing the sample by using deionized water and absolute ethyl alcohol for three times to thoroughly remove unreacted ions and impurities adsorbed on the surface, and then drying the sample in a vacuum oven at 60 ℃ for 12 h to obtain the electrocatalyst.
  5. 5. The method for preparing the anti-poisoning electrocatalytic ammoxidation catalyst based on a bimetal-polyoxometallate interface as set forth in claim 4, wherein in the step S1, if the concentration of hydrochloric acid is lower than 1 mol/L, the nickel oxide layer is difficult to completely remove, resulting in uneven surface loading of subsequent metal ions, and if the concentration is too high (> 5 mol/L) or the soaking time is too long, the nickel matrix may be corroded, the collapse of the surface pore structure may be caused, and the specific surface area may be reduced.
  6. 6. The method of preparing an anti-poisoning electrocatalytic ammoxidation catalyst based on a bi-metal-polyoxometallate interface as set forth in claim 4, wherein in step S2, if the solution is not sufficiently stirred or the metal salt ratio deviates from 1:1, it may cause incomplete coordination between Ni2+ and POM anions to form a heterogeneous complex, and if the solution is cloudy or precipitates, it indicates that the pH is too high (> 6) and should be properly adjusted to maintain the transparency of the solution to ensure the structural integrity of the POM.
  7. 7. The method for preparing the anti-poisoning electrocatalytic ammoxidation catalyst based on a bimetallic-polyoxometallate interface as set forth in claim 4, wherein in the step S3, if the reaction temperature is lower than 150 ℃, the POM crystal nucleus formation rate is too slow, a disordered deposition layer is easy to generate, if the reaction temperature is higher than 200 ℃, the POM framework is partially dehydrated and decomposed to generate an amorphous phase, if the reaction time is lower than 6 h, the Ni and Cu species are unevenly distributed, and if the reaction time exceeds 12 h, crystal grains are excessively grown, and the specific surface area and the active site exposure are reduced.
  8. 8. The method for preparing an anti-poisoning electrocatalytic ammoxidation catalyst based on a bi-metal-polyoxometallate interface as set forth in claim 4, wherein in step S4, if only water washing is used without using ethanol, the sample is liable to shrink in structure or crack in surface due to capillary water evaporation during drying.
  9. 9. The method for preparing the poisoning-resistant electrocatalytic ammoxidation catalyst based on a bimetal-polyoxometallate interface according to claim 4, wherein in the step S2, the soluble copper salt is at least one selected from copper nitrate trihydrate, copper nitrate hexahydrate, copper chloride dihydrate, copper sulfate pentahydrate and copper acetate, the polyoxometallate is at least one selected from sodium dodecyl tungsten phosphate, potassium dodecyl tungsten phosphate, phosphomolybdic acid, silicotungstic acid and silicomolybdic acid, and the polar solvent is at least one selected from deionized water, ethanol, water-ethanol mixed solution, N-dimethylformamide and ethylene glycol.
  10. 10. The method for preparing an anti-poisoning electrocatalytic ammoxidation catalyst based on a bi-metal-polyoxometalate interface according to claim 4, wherein in step S2, a second soluble transition metal salt is added in addition to the copper salt, the total amount of the second soluble transition metal salt and the copper salt is equal to the amount of the polyoxometalate, and the second soluble transition metal salt is at least one selected from cobalt chloride, ferric nitrate and manganese chloride.

Description

Anti-poisoning electrocatalytic ammoxidation catalyst based on bimetallic-polyoxometallate interface and preparation method thereof Technical Field The invention relates to the technical field of electrocatalytic materials, in particular to an anti-poisoning electrocatalytic ammonia oxidation catalyst based on a bimetallic-polyoxometallate interface and a preparation method thereof. Background Ammonia (NH 3) has been attracting attention in recent years in the "green hydrogen-green ammonia" energy system as a high energy density (12.7 MJ/L), zero carbon fuel and important chemical raw materials, and electrocatalytic ammoxidation reactionOr further oxidized to) Can realize high-value conversion of nitrogen resources under mild conditions, and simultaneously replace an anodic Oxygen Evolution Reaction (OER), obviously reduce the hydrogen production energy consumption of electrolyzed water (theoretical voltage is reduced from 1.23V to 0.06V), however, the practical application of the AOR is limited by the lack of efficient, stable and low-cost catalysts Ammoxidation (AOR) is considered to be an important electrocatalytic process that achieves both nitrogen resource ramp up and green hydrogen production under mild conditions. However, the existing non-noble metal catalyst has the problems of metal dissolution, rapid deterioration of catalytic activity and the like, and the industrial application of the non-noble metal catalyst is severely restricted, wherein the non-noble metal bimetallic alloy such as copper, nickel and the like has good catalytic activity and cost advantages. However, electrochemical dissolution and surface deactivation are liable to occur in an actual electrolyte, so that a novel electrocatalytic material with stable structure, accurate interface regulation and control and excellent catalytic performance is needed. For the problems in the related art, no effective solution has been proposed at present. Disclosure of Invention The invention aims to provide an anti-poisoning electrocatalytic ammoxidation catalyst based on a bimetallic-polyoxometallate interface and a preparation method thereof, so as to solve the problems in the background art. In order to achieve the above purpose, the present invention provides the following technical solutions: an anti-poisoning electrocatalytic ammoxidation catalyst based on a bimetal-polyoxometallate interface, wherein the catalyst is a composite material formed by in-situ growth on a pretreated nickel foam substrate through a hydrothermal method; the composite material comprises nickel ions provided by the dissolution of the nickel foam, exogenously introduced copper ions and complete Keggin type polyoxometallate anions, wherein the nickel ions and the copper ions form a stable bi-metal-polyoxometallate interface structure through bridging oxygen atoms in a polyoxometallate anion skeleton, and the bi-metal-polyoxometallate interface structure is used for synergistically catalyzing ammoxidation reaction under alkaline conditions to generate nitrate. Further, the molar ratio of nickel ions to copper ions is 1:1. Further, the polyoxometalate anion is selected from the group consisting of phosphate tungstate anions #) Phosphate radical anion [ ]) Silicotungstic acid radical anion [ ]) Or silicomolybdate anions) At least one of them. The preparation method of the poisoning-resistant electrocatalytic ammoxidation catalyst based on the bimetallic-polyoxometallate interface specifically comprises the following steps: S1, pretreatment of a carrier, namely sequentially placing commercial nickel foam with the size of 1 cm multiplied by 4 cm into 3 mol/L hydrochloric acid solution, acetone, deionized water and absolute ethyl alcohol for ultrasonic cleaning, and soaking each solvent for 20 min; s2, preparing precursor solution, reacting and assembling, and weighing 1 mmol nickel nitrate hexahydrate @ the precursor solution ) And 1 mmol sodium dodecyl phosphate) Dissolving in 40 mL deionized water, magnetically stirring to form a light green transparent solution, completely immersing the nickel foam pretreated in the step S1 into the solution, and sealing in a 50 mL polytetrafluoroethylene lining reaction kettle; S3, performing hydrothermal reaction to generate a Ni-PTA (Cu) compound, heating the reaction kettle in the S2 to 180 ℃ and preserving heat for 8 h; S4, washing and drying the sample, naturally cooling to room temperature after the reaction is finished, taking out the sample, alternately ultrasonically washing the sample by using deionized water and absolute ethyl alcohol for three times to thoroughly remove unreacted ions and impurities adsorbed on the surface, and then drying the sample in a vacuum oven at 60 ℃ for 12 h to obtain the electrocatalyst. Further, in the step S1, if the concentration of hydrochloric acid is lower than 1 mol/L, the nickel oxide layer is difficult to completely remove, so that the subsequent metal ions are unevenly loaded on the s