Preparation And Properties Of Electrocatalysts For Direct Alcohol Fuel Cell

As a kind of green energy sources,direct alcohol fuel cells have been receiving considerable attention in recent years.The study of direct alcohol fuel cells have been encountered with many problems,including the exploration of anode electrocatalysts with high catalytic performance.Taking the advantages of good electrocatalytic activity and stability,the preparation and property of palladium-based nanocomposites have attracted lots of interest.In this dissertation,palladium-gold/carbon nanoshell and palladium-containing polyoxometallate/graphene nanocomposites are prepared by chemical approaches.The morphology and elemental composition are analyzed by characterizations such as transmission electron microscopy,scanning electron microscopy,infrared spectroscopy,X-ray photoelectron spectroscopy and Raman spectroscopy.The electrochemical performance of the nanocomposites towards methanol,ethanol,ethylene glycol and glycerol oxidation in alkaline electrolyte is investigated by cyclic voltammetry and chronoamperometry,and the nanocomposites with better electrochemical performance are screened.In the investigation of palladium-gold/carbon nanoshell composite,the product optimized by adjusting the position of nanoparticles on carbon nanoshell and the mass ration for metals,shows relatively high electrocatalytic activity and stability towards the oxidation of organic molecules such as methanol.Moreover,two kinds of nanocomposites are obtained in the electrochemical property study of palladium-containing polyoxometallate/graphene composites.The composite composed by graphene and polyoxometallate containing palladium and selenium,possesses better electrocatalytic activity and stability towards the oxidation of four alcohols like methanol,in comparison with commercial 10% Pd/C catalyst;while the other one,which consists of graphene and polyoxometallate containing palladium and tellurium,also exhibits good electrocatalytic properties towards the oxidation of ethylene glycol and glycerol.Experimental results show that,the as-prepared palladium-gold/carbon nanoshell and palladium-containing polyoxometallate/graphene nanocomposites own promising prospect in the application of electrocatalyst for direct alcohol fuel cells.