Ga δ+ -Ti cus 4+ Dual-Site Synergistic Catalyst with Indium-Regulated Acidic Environment for Propane Dehydrogenation

As a direct, atom-economical route for propylene production, propane dehydrogenation (PDH) has received increasing attention. In this work, a series of GaTi catalysts is constructed by in situ incorporation of Ga atoms into the TiO 2 lattice. The Ga δ+ -coordinatively unsaturated Ti 4+ (Ti cus 4+ ) dual-site catalyst exhibits significantly lower activation energies toward propane. Meanwhile, the Ga δ+ center promotes C–H bond activation and cleavage via Ga–H intermediates. Therefore, under the dual-site synergistic effect, the catalyst boosts propane conversion. Furthermore, In atoms are introduced to the dual-site system. The C–C bond cleavage induced by strong acid sites is intensely suppressed by the acidic microenvironment regulation effect of In, leading to enhanced propylene selectivity and anticoke ability. As a result, with the In-enhanced Ga δ+ -Ti cus 4+ dual-site synergistic effect, the obtained 6Ga2InTi catalyst achieves 68% propane conversion, 75% propylene selectivity, and over 90% activity retention after four regeneration cycles.