First-principles statistical mechanics study of the stability of a sub-nanometer thin surface oxide in reactive environments: CO oxidation at Pd(100)

TL;DR

This study uses multiscale modeling to investigate the stability of sub-nanometer surface oxides on Pd(100) catalysts during CO oxidation, revealing dynamic oxidation-reduction processes critical for catalytic activity.

Contribution

It introduces a first-principles statistical mechanics approach to analyze surface oxide stability under realistic reactive conditions, providing new insights into catalyst surface dynamics.

Findings

Surface oscillates between thin oxide and CO adlayers.

Oxidic patches form and reduce dynamically during catalysis.

Surface structure influences catalytic efficiency.

Abstract

We employ a multiscale modeling approach to study the surface structure and composition of a Pd(100) model catalyst in reactive environments. Under gas phase conditions representative of technological CO oxidation (~1 atm, 300-600 K) we find the system on the verge of either stabilizing sub-nanometer thin oxide structures or CO adlayers at the surface. Under steady-state operation this suggests the presence or continuous formation and reduction of oxidic patches at the surface, which could be key to understand the observable catalytic function.