Effect of temperature on CO oxidation over Pt(111) in two-dimensional confinement.

Abstract

Confined catalysis between a two-dimensional (2D) cover and metal surfaces has provided a unique environment with enhanced activity compared to uncovered metal surfaces. Within this 2D confinement, weakened adsorption and lowered activation energies were observed using surface science experiments and density functional theory (DFT) calculations. Computationally, the role of electronic and mechanical factors responsible for the improved activity was deduced only from static DFT calculations. This demands a detailed investigation on the dynamics of reactions under 2D confinement, including temperature effects. In this work, we study CO oxidation on a 2D graphene covered Pt(111) surface at 90 and 593K using DFT-based ab initio molecular dynamics simulations starting from the transition state configuration. We show that CO oxidation in the presence of a graphene cover is substantially enhanced (2.3 times) at 90K. Our findings suggest that 2D confined spaces can be used to enhance the activity of chemical reactions, especially at low temperatures.