Design of PtZn nanoalloy catalysts for propane dehydrogenation through interface tailoring via atomic layer deposition†
Supported Pt nanoparticles are widely used for the catalytic dehydrogenation of propane to propene. Monometallic Pt catalysts are subject to fast deactivation. A successful strategy for stabilization is alloying Pt with a second metal. In this study, we present a novel approach for the precise formation of bimetallic nanoparticles via tailoring of the interface between metal nanoparticles and the support. An ultra-thin functional layer of ZnO is deposited via atomic layer deposition on SiO2. The supported Pt nanoparticles undergo a phase transformation and form Pt1Zn1 alloy nanoparticles under reductive thermal treatment. The resulting Pt1Zn1 catalyst showed a high and stable selectivity to propene over 12 hours of time on stream. The activity of the Pt1Zn1 catalyst was 1.5 times higher than that of a catalyst of the same composition prepared by incipient wetness impregnation. The nanoalloy formation causes electronic and geometric modification of Pt which reduces side reactions and leads to a stable and active propane dehydrogenation catalyst.