Research On Non-carbon-based Membrane Electrodes For Hydrogen Production By Anion Exchange Membrane Electrolysis Of Water

Anion exchange membrane（AEM）water electrolysis hydrogen production has the advantages of both proton exchange membrane（PEM）water electrolysis hydrogen production and alkaline water electrolysis hydrogen production,with high hydrogen production purity and low cost,attracting many researchers to its Do in-depth research.However,the current AEM electrolysis of water for hydrogen production has not yet met the requirements of industrial applications.The key is that the non-precious metal catalysts used have not yet met the application requirements in terms of stability.Moreover,commercial catalysts are noble metal catalysts supported by carbon.Due to the instability of carbon in alkaline medium,the agglomeration and detachment of the catalyst will occur,resulting in the decline of the performance and stability of AEM electrolysis water for hydrogen production.At the same time,the high cost of noble metal catalysts Cost also hinders its large-scale application.Therefore,developing a non-precious metal catalyst with simple preparation method,low cost and good stability is an effective measure to promote the industrial application of AEM electrolysis of water for hydrogen production.Studies have shown that non-carbon-based supports,such as TiN and BN,have excellent stability and electrical conductivity better than carbon supports under alkaline conditions.Firstly,the Co（OH）₂-Co₃O₄/TiN oxygen evolution catalyst was prepared by hydrothermal method and calcination treatment with non-carbon-based support TiN as the support,cobalt acetate and ammonia water as the raw materials.The Co（OH）₂-Co₃O₄/TiN catalyst was used as the anode catalyst to prepare the membrane electrode for the upper battery test.At 1 mol/L KOH at 50℃,the battery current density was 445 mA cm^-2 at 2 V.At a current density of 400 mA cm^-2,the battery has a stable operation time of>85 h,the corresponding battery voltage is basically stable at 2.1 V,and the energy consumption for hydrogen production is 4.8 kWh Nm^-3,showing good electrochemical performance.In order to further improve the performance of the catalyst,the CoP@TiO₂ oxygen evolution catalyst was prepared by calcining and phosphating the Co（OH）₂-Co₃O₄/TiN catalyst with sodium hypophosphite as the phosphorus source.The CoP@TiO₂ catalyst was used as the anode catalyst to prepare the membrane electrode for the upper battery test.At 1 mol/L KOH at 50℃,the battery current density was 792 mA cm^-2 at 2 V.At a current density of 300 mA cm^-2,the battery has a stable operation time of>100 h,an average voltage of 2.05 V,and an energy consumption of 4.4 kWh Nm^-3 for hydrogen production,showing excellent electrochemical performance.In order to solve the problems of poor stability and high cost of the cathode diffusion layer,NiCoP/NF bifunctional catalysts were prepared with low-cost and corrosion-resistant nickel foam（NF）as the substrate.The NiCoP/NF catalyst combines the catalytic component with the diffusion layer and the exchange membrane to form a membrane electrode.The membrane electrode prepared by NiCoP/NF catalyst was tested on the upper battery,and the battery current density was 237 mA cm^-2 at 2 V at 1 mol/L KOH at 50℃.At a current density of 300 mA cm^-2,the battery has a stable operation time of>150 h,the corresponding battery voltage is basically stable at 2.3 V,and the energy consumption for hydrogen production is 4.9 kWh Nm^-3,showing good electrochemical performance.