Promoted propane dehydrogenation over Pt-In intermetallics via classic strong metal-support interaction

Abstract

The classic strong metal-support interaction (SMSI), characterized by the encapsulation of metal nanoparticles within suboxide layers, is a promising strategy for designing robust catalysts. However, applying this strategy to the high-temperature propane dehydrogenation (PDH) process, which is an important petrochemical process for the industrial production of propylene, is rarely reported. Herein, we demonstrate an SMSI-type PDH catalyst, composed of subnanometric Pt₂In₃ clusters encapsulated by an In₂O_3-x overlayer, exhibiting high stability and selectivity. During a 160-h on-stream test, it showed a slight activity decline (k_d = 0.002 h⁻¹) and maintained 99.5% propylene selectivity. The excellent performance is attributed to the dual role of the In₂O_3-x overlayer, which not only prevents the sintering of the Pt₂In₃ clusters but also modifies the electronic structure of Pt atoms via interfacial interaction, thus facilitating the generation and propylene desorption. Meanwhile, the Pt₂In₃ intermetallics disrupt large Pt ensembles and introduce electron-rich Pt atoms, suppressing side reactions and enhancing propylene desorption.