Research Progress on Catalyst Design and Reaction Mechanisms for Heterogeneous Oxygen Oxidation of Light Hydrocarbons
Catalytic oxidation is a pivotal technology for the valorization of light hydrocarbons, with oxidative dehydrogenation (ODH) and epoxidation using molecular oxygen attracting significant interest due to high atom economy and environmental friendliness. This review systematically summarizes recent advances in the oxidative dehydrogenation of light alkanes (ethane, propane) and aerobic epoxidation of light olefins (ethylene, propylene). For rational catalyst design, it elaborates on performance regulation strategies for metal oxide catalysts such as MoVNbTeOx mixed oxides, NiO-based, and V-based systems, as well as carbon/boron-based non-metal catalysts in alkane ODH, and silver- and copper-based catalysts in alkene epoxidation. Strategies include regulating the oxidation state of active sites, exploiting strong metal-support interactions, engineering particle size and crystal facets, and promoter modification. At the mechanistic level, combining density functional theory calculations with in situ characterization, the review examines C–H bond activation and alkene desorption pathways in ODH, and oxygen insertion routes and competing side reactions in epoxidation. Special attention is given to the dynamic evolution of electrophilic and nucleophilic oxygen species and their decisive role in selectivity. Persistent challenges include suppressing over-oxidation and overcoming the conversion–selectivity trade-off. Future directions propose precise design of active centers, development of inherently safer processes, and in-depth analysis of complex reaction networks, supporting the green transition of the chemical industry.