Research Progress of Catalysis for Low-Carbon Olefins Synthesis Through Hydrogenation of CO₂

Fossil fuel consumption, global warming, climate change, and price fluctuation of fuels push scientists to search for alternative ways to produce fuel. From the viewpoint of CO₂ capture and utilization, using CO₂ as raw material to produce value-added products is attractive because it can not only alleviate global warming but also offers a solution to replace dwindling fossil fuels. Especially the technique of CO₂ hydrogenation to low-carbon olefins including ethylene, propylene and butylene is highly attractive. However, due to the extreme inertness of CO₂ and a high C-C coupling barrier, the conversion of CO₂ and selectivity of C_2-4 are not high. In addition, methane, as one main product in CO₂ hydrogenation, inhibits the production of other long-chain hydrocarbons. So it is decisive to design effective catalyst system to increase C_2-4 selectivity while decrease CH₄ selectivity. This review focuses on two routes for low-carbon olefins synthesis from CO₂ hydrogenation. The first route is direct synthesis of low-carbon olefins through CO₂ hydrogenation process. The catalyst supports, promoters and bimetallic active components are inextricably related with hydrogenation of CO₂ to lower olefins, which was reviewed in detail. The other route is indirect route for low-carbon olefins synthesis through hydrogenation of CO₂ to methanol and subsequently methanol to lower olefins, which is briefly discussed.