States of Pt/CeO2 catalysts for CO oxidation below room temperature

CO molecules can be efficiently oxidized over Pt/CeO2 catalysts, but the stability and reactivity of differ-ent states of Pt in the catalysts are still unclear. Here we combine experimental and computational meth-ods to characterize Pt/CeO2 catalysts subjected to reductive and oxidative pre-treatments and exposed CO oxidation reaction conditions. Particles of metallic Pt, known to be catalytically active at elevated tem-perature, are shown to be precursors for the formation, under operando conditions, of more stable PtOx particles that enable CO oxidation below room temperature. These PtOx particles are similarly stable to - but more active than - atomically dispersed Pt2+ species. The results and approaches presented this study illustrate the complex response of catalytic materials to reaction conditions and pave the way for future efforts to improve Pt/CeO2 and similar catalysts using dedicated pre-treatment strategies.(c) 2023 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).