Research On Novel Oxygen Evolution Electrode For Proton Exchange Membrane Water Electrolysis

The solid polymer electrolysis,which is mainly based on the proton exchange membrane?PEM?,has the advantages as high efficiency,high hydrogen purity,high pressure tolerance,compact structure,safety and environmental protection and good adaptability for fluctunt power,which make PEM water electrolysis quite suitbale for the conversion of the renewable energy power into hydrogen energy without carbon emission.The main factors of limiting the industrial application of the PEM water electrolysis are high system cost and relatively low durability,which mainly come from expensive catalyst.By improving the activity and stability of the anode catalyst IrO₂,the compsite catalyst can obtain great enhancement on performance and durability,which contributes to the cost saving of the noble catalysts.In this paper,tin dioxide was chosen as the basic catalyst support because of its low price,good stability,highly controllable microstructure.In order to overcome the disadvantages of tin dioxide on surface activity and conductivity,the hydrothermal method was used to modify the tin dioxide support by Co doping.The research shows that Co doping refines the supported IrO₂ particles,which was significantly increased the active area of the IrO₂ component,at the same time,it also enhanced the strong interaction between the doped tin dioxide support and the IrO₂ particles and reduces the valence state of Ir and enhances the activity and durability of the composite catalyst.The 20 at%Co-doped tin dioxide increases the specific surface area to131.92 m²·g^-1,and the conductivity of the composite catalyst 40IrO₂/Co_0.2Sn_0.8O₂ is significantly improved to 1.17·10⁰ S cm^-1.The composite catalyst performs a cell voltage of 1.748 V under 1 A·cm^-2 and 80?,which shows that Co doping has a significant effect on the enhancement of catalytic activity.In order to obtain high stability and active oxygen evolution reaction?OER?catalyst,a core-shell structure of IrO₂@RuO₂ oxygen evolution catalytic material was synthesized by surface modification/precipitation method.The comparative study of the IrO₂@RuO₂ with commercial RuO₂ and unsupported IrO₂ shows that the core-shell structure of IrO₂@RuO₂ promotes the intimate contact of the two oxides,and at the same time covers the well-defined small particles on the surface of RuO₂,which provide a high concentration of active sites at the interface electrolyte/catalyst.These catalytic benefic effects achieve a synergistic effect between the intrinsic activity of RuO₂ and the stability of IrO₂ and thus show the best activity.As a result,the IrO₂@RuO₂ catalyst perform a cell voltage of 1.653 V under 1 A·cm^-2 and 80?,which successfully exceed the unsupported IrO₂.Meanwhile,the IrO₂@RuO₂ catalyst shows better stability in the 300h durability test.Therefore,this paper is beneficial to design a suitable,high efficient and stable SPE oxygen evolution electrode.