Efficient Photocatalytic Propane Direct Dehydrogenation to Propylene Over PtO2 Clusters

Abstract

The direct dehydrogenation of alkanes to olefins under mild conditions is challenging due to the inert nature of alkyl C─H bonds. Herein, an efficient photocatalytic system is developed for propane direct dehydrogenation (PDH) to propylene, consisting of ≈1.30 nm sized PtO₂ clusters immobilized on a layered double hydroxide -derived ZnO/Al₂O₃ support (LD-Pt_n). Under UV excitation (365 nm), photogenerated holes in ZnO migrate to Pt sites at PtO₂/ZnO interfaces, thereby activating and dissociating C─H bonds in propane. A propylene production rate of almost 1 mmol g⁻¹ h⁻¹ and a nearly 100% selectivity are achieved for the compositionally optimized LD-Pt_n photocatalyst. Control experiments and density functional theory calculations further verify that the excellent photocatalytic PDH performance of LD-Pt_n stems from synergism between ZnO semiconductor and the loaded Pt species. This work identifies a promising new route for direct production of olefins from alkanes.