Mechanism of Methanol Decomposition over Single-Site Pt₁/CeO₂ Catalyst: A DRIFTS Study

Single-site catalysts have drawn broad attention in catalysis because of their maximum atomic utilization and unique catalytic performance. Early work in our group has shown a 40-fold higher activity of methanol decomposition over single-site Pt₁/CeO₂ catalyst than CeO₂ supported 2.5 nm Pt nanoparticles, while a molecular-level understanding of such enhancement is lacking. Herein, the reaction mechanism of methanol decomposition over Pt₁/CeO₂ was carefully investigated using in situ DRIFTS, and a reaction pathway was proposed. Methanol molecules were dissociatively adsorbed on nanoceria support first, followed by the diffusion of as-formed methoxy species onto Pt single sites where the dehydrogenation occurs and results in the weakly bonded CO. The ease of methanol dissociative adsorption on nanoceria support and the tailored electronic property of Pt₁ via the metal-support interaction are believed to be strongly correlated with the high activity of Pt₁/CeO₂.