Palladium-Alloy Based Nanostructure For The Application In Electrocatalysis

Fuel cells have attracted widespread attention due to their advantages including environmentally friendly nature,renewable energy supply,and high energy density.Palladium,a noble metal,is favored for its excellent electrocatalytic activity and tolerance to CO poisoning.However,the electrocatalytic oxidation activity and stability of monometallic palladium cannot achieve ideal catalytic performance.Therefore,by alloying Pd with other metals to regulate its electronic structure,the electrocatalytic performance of Pd is expected to be improved.In this dissertation,palladium-nickel alloy braided tubular nanotube,palladium-copper hollow nanosphere,and palladium-cobalt/porous carbon nanocomposite were prepared using co-precipitation,hydrothermal,and one-pot methods,respectively.The morphology and structure of the prepared materials were analyzed by characterization techniques such as scanning electron microscopy,X-ray photoelectron spectroscopy,X-ray diffraction,and so on.The electrocatalytic oxidation performance towards organic molecules,including methanol,ethanol,ethylene glycol and glycerol,of the prepared palladium-nickel alloy nanostructures,palladium-copper hollow nanospheres,and palladium-cobalt/porous carbon nanocomposites was examined.Electrochemical results showed that among the different recipes,Pd₂Ni alloy nanostructure with a Pd/Ni molar ratio of 2:1 exhibited high Pd mass activity and stability for the oxidation reaction of methanol,ethanol,ethylene glycol,and glycerol,and also owned good resistance to CO poisoning.In the study of palladium-copper hollow nanospheres,Pd Cu hollow nanospheres with a Pd/Cu molar ratio of 1:1 not only exhibited good electrocatalytic performance towards the electrooxidation of various alcohol molecules in alkaline solution,but also had good tolerance to CO poisoning.Besides,the Pd₃Co/porous carbon nanocomposites in a Pd/Co molar ratio of 3:1 showed good Pd mass activity and stability for the electrocatalytic oxidation of alcohol molecules such as ethanol.The electrochemical results also revealed that the electrochemical performance of the prepared palladium-alloy-based nanostructures was better than that of commercial 10%Pd/C catalyst,indicating good application prospects in the field of direct alcohol fuel cells.