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

Heterogeneous bimetallic catalysts are widely used in industrial processes, and the structural features of the bimetallic catalysts have profound impacts on their properties in numerous catalytic processes. Bimetallic nanoclusters with particle sizes ≤1 nm have shown better performances in various catalytic reactions in comparison to conventional bimetallic nanoparticles with sizes above 1 nm. Despite the progress made in recent years in the synthesis and catalytic studies of bimetallic nanoclusters, achieving a fundamental understanding of the structure–reactivity relationships at the molecular and atomic levels remains challenging because of the complexity of the bimetallic catalysts with particle sizes ≤1 nm. In this work, we have studied the structural features of supported bimetallic PtSn species with different sizes (∼0.6 to ∼1.6 nm), which is shown to be associated with the size-dependent formation process of bimetallic PtSn species according to theoretical modeling and experimental studies. Furthermore, the catalytic consequences of their size-dependent structural features are reflected in the dehydrogenation of propane to propylene, in which the subnanometer PtSn clusters are more active than the PtSn alloy nanoparticles.