PtZn intermetallic nanoalloy encapsulated in silicalite-1 for propane dehydrogenation

Propane dehydrogenation (PDH) is one of the most effective methods to produce propylene. But the industrial Pt-based catalysts often suffer from short-term stability under the high temperature reaction environment (500–700°C) via sintering and coke deposition. Herein, stable PDH reaction in high propylene yield has been achieved by the confinement of Pt–Zn intermetallic alloys (IMAs) in the channels of silicalite-1. Single-site Zn in the MFI framework was found to play a key role on assisting and stabilizing the PtZn IMAs for efficient PDH. By the cooperative action of the spatial confined PtZn IMAs and the lattice confined framework Zn, high propylene selectivity (>99%) without obvious deactivation was realized on the as-developed catalyst (PtZn@S-1) under 600°C even after 90 h. The low deactivation constant (0.003 h −1 ) was 6 times lower than that of the industrial PtSn catalyst.