CO2 Hydrogenation to Light Olefins and Single Hydrocarbons: Active Sites and Synergy in Oxide–Zeolite Catalysts

Abstract

Catalytic CO₂ hydrogenation to light olefins and single hydrocarbons represents a crucial pathway for achieving carbon neutrality and sustainable chemical production. Oxide–zeolite (OX-ZEO) catalysts have shown remarkable potential due to their high selectivity for target products. However, a systematic understanding of their active sites remains notably underdeveloped. This review provides a comprehensive analysis of the active sites in OX-ZEO catalytic systems for CO₂ hydrogenation to light olefins and single hydrocarbons. For the oxide components, we critically examine the controversial nature of active sites in metal oxide, including oxygen vacancies, special electronic state metal ions and dual-site synergy, with special focus on the debated ZnZrO_x system. For zeolite, we analyze the relationship between zeolite properties and product distribution, including acid location and acid property. Significantly, we emphasize the interactions between oxide and zeolite components and their influence on catalytic behavior. Finally, we point out that future catalyst design should focus on understanding and utilizing the interactions between active sites.