Chemical and Spatial Dual-Confinement Engineering for Antisintering Bimetal Cluster Catalyst: Framework Zinc-Stabilized Pt–(O–Zn)_x Sites for Propane Dehydrogenation

Bimetal cluster catalysts present boosted catalytic performance in numerous reactions due to their coordinatively unsaturated metal sites and synergy. Nevertheless, constructing ultrafine and stable bimetal cluster catalysts that can be well applied under harsh high-temperature reaction conditions is still a tough challenge. Herein, we propose a spatial and chemical dual-confinement strategy to design hierarchical ZSM-5 zeolite-confined PtZn bimetal catalysts with ultrafine clusters (ca. 1.2 nm) and high stability against sintering, which can be controllably synthesized via a microwave-assisted one-pot hydrothermal approach. The optimized PtZn@ZSM-5 cluster catalyst exhibits remarkably boosted propane dehydrogenation (PDH) performance, with a propane conversion of ca. 60% and a propylene selectivity of >96% (WHSV = 3 h–1, 600 °C). Both experimental and theoretical studies demonstrate that Pt species are well anchored by the hierarchical pores and framework zinc, constructing highly dispersed active Pt–(O–Zn)x species responsible for the boosted catalytic performance. This work affords a facile and general dual-confinement strategy to synthesize ultrafine bimetal cluster catalysts for PDH, which can be well extended to other catalyst systems, such as RhZn@ZSM-5 and IrZn@ZSM-5.