Elucidating the active sites in CuPt/CeO2 model catalysts: A spectroscopic study on methanol reactivity

The surface reactivity of methanol over model catalysts composed of Cu, Pt, and CuPt nanoparticles supported on {111}-faceted CeO 2 octahedra was investigated via in-situ DRIFTS. Characterization confirmed the formation of a Cu 3 Pt alloy, enhanced reducibility, and a stronger Pt-ceria interaction in the Cu 4 Pt 1 /Ce–O catalyst. Spectroscopically, Cu-containing samples exhibited a characteristic methoxy band (~ 2877 cm −1 ). In the bimetallic catalyst, this band appeared red-shifted, evidencing electronic/geometrical modifications associated with a ligand effect that weakens the C-H bond. Furthermore, reactive interfacial Pt-ceria carbonyl species (~ 2017 cm −1 ) were identified. Crucially, while unstable on monometallic Pt, these active sites were thermally stabilized up to 300℃ in the bimetallic system, correlated with its superior catalytic performance in methanol-involving reactions.