A Study On Anodic Catalyst In Solid Polymer Electrolyte Water Electrolysis

Hydrogen is an ideal energy resource, and hydrogen production by water electrolysis has a bright future. Solid Polymer Electrolyte (SPE) water electrolysis system, which offers several advantages over traditional technologies including greater energy efficiency, higher production rates, better safe reliability and more compact design, will play more and more important role in water electrolysis industry; however, higher cost limits its further application. In order to lower the cost, researchers focus on developing cheaper membrane, improving catalyst activity, lowering catalyst loading, improving MEA procedure, increasing operating temperature and pressure and optimizing structure of water electrolysis cell.Brushing and thermal decomposition methods are used to prepare SPE anode catalyst layer in this work to improve electrode life and catalyst activity, lower expensive metal oxide catalyst loading and reduce electrode preparation cost, and then effects of preparation conditions on catalyst are studied.IrO2 catalyst is adhered to Ti mesh using PVDF as adhesive and DMF as solvent by brushing to make anode catalyst layer, which is then tested by cyclic voltammetary, electrochemistry impedance spectroscopy, scanning electronic microscope and water electrolysis cell performance. The results show that catalyst layer has the largest catalyst active surface, lowest layer resistance and best cell performance when dried in oven and when the adhesive proportion is 1.1. IrO2-CoOx catalyst layer is made by thermal decomposition method based on DSA technology. H2IrCl6与CoCl2 mixed solution is brushed onto Ti meshes, which are then annealed at 450℃, 500℃and 550℃respectively. The results show that catalyst particle size increases and the material becomes more crystalline with the increase of annealing temperature, leading to smaller catalyst active surface and higher electronic conductivity, as well as more severe substrate oxidation and lager anode resistance. The best annealing temperature is 500℃. Catalyst active surface has a"volcano-plot"relation with Co proportion. When Co proportion is 0.3, the catalyst layer has the largest active surface, lowest layer resistance and best cell performance. According to cell performance, thermal decomposition method is better than brushing method.