The Commonality of Surface Processes in Electrocatalysis and Gas-Phase Heterogeneous Catalysis

Publisher Website
Google Scholar
Abstract
This review has been structured to provide a bridge between the fields of electrocatalysis and gas-phase catalysis on solid surfaces. Considerable emphasis has been placed upon the characterization of adsorbed species on electrocatalysts. Electrocatalytic studies show surface interactions between adsorbed CO and H on Pt, which parallel similar studies in the gas phase. The application of high surface area electrocatalysts in real systems draws heavily upon the experience gained in the gas-phase field, particularly with reference to an understanding of porous electrode structures and the measurements of kinetic parameters for highly dispersed materials. As in gas-phase heterogeneous catalysis, highly dispersed electrocatalysts show crystallite size effects. The electrochemical reactions most sensitive to crystallite sizes are charge transfer reactions involving strongly bonded surface species. These electrochemical crystallite size effects are electronic rather than geometric in nature. Perhaps the most dramatic exposé concerning the commonality of surface reactions in both gas-phase and electrochemical systems is obtained for the reactions of hydrogen molecules on Pt. The two fields complement each other to the extent that the same reaction step (dual-site dissociative chemisorption) is identifiable at 10−8 Torr on a clean polycrystalline Pt wire and in 96 wt% H3PO4 at 160°C on highly dispersed Pt supported on graphitized carbon. It is to be expected that further gains in comprehension will be made by both electrocatalysis and gas-phase catalysis by the incorporation of complementary ideas with results from solid-state studies of surfaces under ideal conditions.

This publication has 81 references indexed in Scilit: