Surface Characterisation and Electrochemical Behaviour of Well- Defined Pt-Pd(111)Single Crystal Surfaces:A Comparative Study Using Pt(111)and Palladium-modified Pt (111)Electrodes.

摘要

The need to understand the key structural parameters governing the electrocatalytic behaviour of metal surfaces continues to provide a strong impetus towards fundamental studies of electrosorption [1J.To this end,systematic variation of surface crystallography [2] and surface modification of well-defined electrodes by adatoms [3] has often been employed to delineate these electrocatalytic trends [4],However,very few electrocatalytic studies of bi-metallic alloy single crystal electrodes have been reported [5,6], Since electronic perturbations associated with alloy phases are almost certainly connected with several high performance catalysts [7],this relative lack of fundamental experimental data constitutes a significant weakness on the part of the surface science approach to electrochemistry.In order to improve this situation,we have embarked upon a research program which utilises a simple modification of the Clavilier method of single crystal manufacture to prepare a series of well-defined bi-metallic bead electrodes.For example,by adding palladium carefully to the molten bead formed from a melted platinum wire,it is possible to control very precisely the bulk composition of the Pd-Pt single crystal that is formed upon cooling.