Lewis acid sites stabilized Pt-Sn clusters for propane dehydrogenation

Al 2 O 3 with high Lewis acid site density and high porosity was synthesized. • Abundant strong Lewis acid sites stabilize Pt-Sn clusters in the PDH reaction. • High porosity endows the catalyst with superior coke tolerance. Pt-based particles supported on alumina are the industrial catalysts for propane dehydrogenation processes. However, the high-temperature reaction conditions promote metal sintering and coke deposition, leading to catalyst deactivation, which constitutes a major technical challenge for this process. In this study, the interplay among the acidity and texture of alumina support, metal–support interaction, and catalyst durability/regenerability was explored. A series of alumina materials with varied acidity and textural properties were prepared by controlling aluminum alkoxide hydrolysis and calcination conditions, producing alumina materials with high Lewis acid site density and porosity. Comprehensive characterizations and propane dehydrogenation tests were performed to investigate how the Lewis acidity and textural properties of the alumina supports influence the deactivation and regeneration behavior of the supported PtSn catalysts. The high density of strong Lewis acid sites effectively anchors metal clusters via strong metal–support interactions, thereby inhibiting sintering and enhancing long-term regenerability. After four reaction-regeneration cycles under simulated industrial conditions, the PtSn/Al-600 catalyst achieved a regeneration rate of 90%. Meanwhile, the ultrahigh surface area and porosity endow the catalyst with high coke accommodation capacity, delaying deactivation by coking. Download: Download high-res image (329KB) Download: Download full-size image