Strain Affects CO Oxidation on Metallic Nanoparticles Non-linearly

Abstract

Adsorption and reaction energies on metal surfaces are known to depend sensitively on strain. How such effects influence catalytic reactions over nanoparticles is, however, largely unexplored. Here we investigate the effect of strain on the catalytic performance of CO oxidation over Pt nanoparticles using scaling relations kinetic Monte Carlo simulations. The catalytic activities are compared with the corresponding results for Pt(111). We find that a moderate expansive strain yields higher catalytic activities for both nanoparticles and extended surfaces. The strong kinetic couplings between different sites on nanoparticles makes the particles respond non-linearly to strain. This is in contrast with Pt(111), which shows a linear response to strain. The present work demonstrates the possibilities with strain-engineering and highlights the limitation in extrapolating results from extended surfaces to nanoparticles.