Effect of Surface Oxide Transformation on CO Oxidation

Abstract

Under sub-atmospheric conditions, many metal catalyst surfaces for CO oxidation transform to the oxide phase with higher catalytic activity than chemisorbed oxygen. The surface phase transformation from metal to its oxide could be by collective oxidation of the adsorbed oxygen sites as soon as their coverage reaches a global critical threshold, or such oxidation may be restricted to small patches of the surface, which is driven by the local coverage. In this communication, we investigate the effect of the latter on the phase diagram and the CO2 production rate behavior using a kinetic Monte Carlo surface reaction lattice gas model for CO oxidation. © 2015, Sociedade Brasileira de Física.