Abstract
The oxidative dehydrogenation of propane with CO(2) (CO(2)-ODP) is a green industrial process for producing propene. Cerium oxide-supported platinum-based (Pt/CeO(2)) catalysts exhibit remarkable reactivity toward propane and CO(2) due to the unique delicate balance of C-H and C[double bond, length as m-dash]O bond activation. However, the simultaneous activation and cleavage of C-H, C-C, and C-O bonds on Pt/CeO(2)-based catalysts may substantially impede the selective activation of C-H bonds during the CO(2)-ODP process. Here, we report that the scattered rare metal oxide (SRO (x) , SR = Ga, In) overlayer on Pt/CeO(2) exhibits extraordinary activity and selectivity for the CO(2)-ODP reaction. With the assistance of Pt, the SRO (x) -Pt/CeO(2) could achieve a propane conversion of 38.13% and a CO(2) conversion of 67.72%. More importantly, the selectivity of the product propene has increased from 33.28% to 88.24%, a level that is even comparable to the outstanding performance of currently reported PtSn/CeO(2) catalysts. A mechanistic study reveals that the strong affinity of the overlayer SRO (x) to the propane reduces the barrier of C-H bond activation and balances the C-H cleavage rates and the C-O bond groups, accounting for the excellent selective CO(2)-ODP performance of SRO (x) -Pt/CeO(2) catalysts. The SRO (x) -modified Pt/CeO(2) strategy offers a novel approach to modulating CO(2)-ODP, thereby facilitating the highly selective preparation of propene.