Catalytic CO oxidation over Pd70Au30(111) alloy surfaces: spectroscopic evidence for Pd ensemble dependent activity

Abstract

Catalytic CO oxidation over Pd(111) and Pd70Au30(111) surfaces was investigated by in situ spectroscopic observations to understand the alloying effect. The reaction behaviour on Pd70Au30(111) is greatly different from that on Pd(111). Pd monomer and dimer ensembles can act as active centers, whereas triangular-shaped trimers and larger ensembles are inactive.