Hydrogen Electrosorption and Oxidation of Formic Acid on Platinum Single-Crystal Stepped Surfaces

Abstract

Hydrogen adsorption and oxidation of formic acid show a pronounced dependence on the structure of single crystal surfaces. The influence of the terrace and step orientation and step density is reflected in both reactions on step surfaces. The multiple states of hydrogen adsorption can be correlated with the nature of adsorption sites. There is a negligible effect of adsorbate-adsorbate interaction on step surfaces. Some lateral repulsion of hydrogen adsorbed on Pt(111) could be inferred. A strong adsorption of bisulphate and sulphate anions on the (111) oriented terraces and step sites considerably affects both reactions. These data show that each crystallographic orientation of the electrode surfaces gives a different electrochemical entity.