Strontium Promoted PtSn/Al₂O₃ Catalysts for Propane Dehydrogenation to Propylene

PtSn/Al₂O₃ and PtSnSr/Al₂O₃ were prepared by the incipient wetness impregnation method. The added Sn and Sr are uniformly distributed on the surface without damaging the original crystal structure and surface texture properties. The addition of Sn not only changes the dispersion of Pt, reduces the reduction temperature of Pt, but also provides electrons to Pt, increases the electron cloud density on the surface of Pt, and reduces the deep propylene adsorption. The addition of Sr reduces the number of total acid sites and strong acid sites, reduces the generation of adverse effects and carbon deposition, slows down the deactivation of the catalyst, and improves the selectivity of propylene. Pt1.5Sn1.5Sr/Al₂O₃ showed the best catalytic reaction performance and remained stable after five cycles of regeneration.