Restructured zeolites anchoring singly dispersed bimetallic platinum and zinc catalysts for propane dehydrogenation

Abstract

Restructuring of a heterogeneous catalyst under reaction conditions is a common phenomenon. Severe restructuring of a catalyst can result in deactivation in many catalytic systems—for example, the catalytic dehydrogenation of propane to propylene. Herein, we report the utilization of catalyst restructuring to improve activity and stability for the propane dehydrogenation reaction. A bimetallic platinum and zinc (Pt1Znm) catalyst protected by an in situ restructured silicalite-1 zeolite is prepared. The catalyst yields outstanding activity (initial conversion of ∼69.2%, initial selectivity of ∼91.1%) with high stability at 580°C, which is better than several commercial catalysts. Characterization shows the singly dispersed bimetallic sites of Pt1Znm serve as the catalytic sites during the reaction. Moreover, the less-stable silicalite-1 zeolite undergoes restructuring during the dehydrogenation reaction, forming a crucial protective layer on the Pt1Znm bimetallic nanocatalysts.