Synthesizing High-Volume Chemicals from CO2without Direct H2Input

Decarbonizing the chemical industry will eventually entail using CO(2)as a feedstock for chemical synthesis. However, many chemical syntheses involve CO(2)reduction using inputs such as renewable hydrogen. In this review, chemical processes are discussed that use CO(2)as an oxidant for upgrading hydrocarbon feedstocks. The captured CO(2)is inherently reduced by the hydrocarbon co-reactants without consuming molecular hydrogen or renewable electricity. This CO(2)utilization approach can be potentially applied to synthesize eight emission-intensive molecules, including olefins and epoxides. Catalytic systems and reactor concepts are discussed that can overcome practical challenges, such as thermodynamic limitations, over-oxidation, coking, and heat management. Under the best-case scenario, these hydrogen-free CO(2)reduction processes have a combined CO(2)abatement potential of approximately 1 gigatons per year and avoid the consumption of 1.24 PWh renewable electricity, based on current market demand and supply.