Reaction-induced dynamic evolution of PtIn/SiO2 catalyst for propane dehydrogenation

Understanding the dynamic evolution of heterogeneous catalysts is crucial yet challenging for elucidating the structure-performance relationships and enabling rational catalyst design. Herein, we reveal that PtIn alloy clusters gradually evolve into Pt3In intermetallic in response to propylene, the product of propane dehydrogenation (PDH) reaction. Specifically, a PtIn1.0/SiO2 catalyst has been fabricated, comprising sub-nanometric PtIn alloy clusters covered by an In0 overlayer, with In3+ species locating at the metal-support interface. During the PDH reaction propylene induces the evaporation of the In0 overlayer, thereby exposing Pt sites. After an induction period, the evolved Pt3In intermetallic (average size ~1.3 nm) exhibits a C3H6 productivity of 145 mol gPt-1 h-1. The alloyed In0 species effectively dilute Pt-Pt ensembles, enhancing propylene selectivity, while the interfacial In3+ species inhibit aggregation of Pt3In intermetallic, ensuring excellent catalytic stability. These findings underscore the critical role of product molecules in shaping active site evolution at the atomic scale.