Size-Dependent Structures and Catalytic Properties of Supported Bimetallic PtSn Catalysts for Propane Dehydrogenation Reaction

Heterogeneousbimetallic catalysts are widely used in industrialprocesses, and the structural features of the bimetallic catalystshave profound impacts on their properties in numerous catalytic processes.Bimetallic nanoclusters with particle sizes <= 1 nm have shownbetter performances in various catalytic reactions in comparison toconventional bimetallic nanoparticles with sizes above 1 nm. Despitetheprogress made in recent years in the synthesis and catalytic studiesof bimetallic nanoclusters, achieving a fundamental understandingof the structure-reactivity relationships at the molecularand atomic levels remains challenging because of the complexity ofthe bimetallic catalysts with particle sizes <= 1 nm. In thiswork, we have studied the structural features of supported bimetallicPtSn species with different sizes (similar to 0.6 to similar to 1.6 nm),which is shown to be associated with the size-dependent formationprocess of bimetallic PtSn species according to theoretical modelingand experimental studies. Furthermore, the catalytic consequencesof their size-dependent structural features are reflected in the dehydrogenationof propane to propylene, in which the subnanometer PtSn clusters aremore active than the PtSn alloy nanoparticles.