Surface Regulation And Anti-CO Poisoning Performance Of Palladium-Based Materials

Fuel cells have become the focus of today’s society taking the advantages of energy saving,high efficiency,low pollution,lightweight and portability.Palladium-based nanomaterials can be used as electrode materials,but are easily affected by the reaction intermediate carbon monoxide in practical applications,which are then poisoned and lose catalytic activity.In order to overcome the influence of carbon monoxide poisoning and improve the lifetime of palladium-based materials,the surface structure mediation should be performed to obtain larger specific surface are,which can effectively improve the electrocatalytic activity and anti-poisoning performance.In this thesis,the surface structure is regulated by preparing various palladium-based alloy nanostructure,in order to improve the electrocatalytic and anti-poisoning performance.In the dissertation,palladium-nickel raspberry nanostructure,palladium-bismuth nanosphere,and star-like PdRuCu ternary alloy nanomaterial were prepared by chemical liquid-phase approach.The morphology and chemical composition of the prepared palladium-based alloy nanomaterials were characterized by techniques including scanning electron microscopy,X-ray diffraction and X-ray photoelectron spectroscopy.The various as-prepared nanomaterials were further investigated in the application towards the electrocatalytic oxidation of alcohol.Firstly,the prepared Pd Ni alloy was treated using phosphotungstic acid to obtain a raspberry nanostructure.Electrochemical results showed that the as-prepared raspberry Pd Ni nanostructure exhibit enhanced mass catalytic activity and anti-poisoning performance towards the alcohol elextrooxidation.Secondly,the as-prepared Pd₃Bi nanospheres not only possess better electrocatalytic activity towards the oxidation of ethanol,ethylene glycol and glycerol in alkaline media,but also shows better durability in amperometric i-t measurement.Besides,CO stripping experiments also reveal the better anti-poisoning performance of Pd₃Bi nanosphere.Finally,the fabrication process of the prepared star-like PdRuCu nanomaterial was also discussed.Electrochemical results present that the as-prepared ternary alloy material shows enhanced mass activity,durability and well-performed CO tolerance in the electrooxidation of alcohol including methanol,ethanol,ethylene glycol and glycerol in the alkaline electrolyte.The prepared Pd-based alloy nanomaterials also own good application prospect in other fields.