Progress in CO2-to-olefins conversion via hydrogenation

HAN Jianxiang; CUI Xiwen; SUN Jian

doi:10.13226/j.issn.1006-6772.GPF25040101

Abstract：Under the dual imperatives of global climate change and energy structure transition,the efficient conversion and utilization of CO2 has emerged as a pivotal pathway toward achieving the"dual carbon"goals.Olefins,as essential chemical feedstock,are traditionally produced through fossil resource-intensive processes characterized by high energy consumption and substantial carbon emissions.Consequently,the catalytic hydrogenation of CO2 to olefins using green hydrogen presents a promising strategy to mitigate greenhouse gas emissions while reducing reliance on petrochemical resources.Against this backdrop,this review systematically summarizes recent advancements in CO2 hydrogenation to olefins,with a particular focus on catalyst design and reaction mechanisms.The review begins with a comprehensive overview of the primary technical routes for CO2-to-olefins conversion,including the CO-mediated pathway and MTO pathway.Subsequently,it elaborates on catalyst design strategies,encompassing the selection of active components(e.g.,Fe-based and Co-based catalysts),the incorporation of promoters(e.g.,alkali metals and transition metals),and the optimization of supports(e.g.,metal oxides and carbon-based materials).These strategies significantly enhance catalytic performance by modulating electronic structures,surface acid-base properties,and the exposure of active sites.Regarding reaction mechanisms,the review provides an in-depth analysis of the CO-mediated and methanol-mediated pathways.The CO-mediated route involves sequential steps such as CO2 adsorption/activation,CO formation/diffusion,and C-C coupling/hydrogenation during FTS.In contrast,the methanol-mediated pathway enables direct CO2-to-olefins conversion via a two-step process,circumventing the Anderson-Schulz-Flory distribution limitation and markedly improving selectivity toward light olefins.Finally,the review oulines future research directions,including the development of more efficient and stable catalytic systems,as well as the design of novel reactors(e.g.,multi-stage or membrane reactors)to enhance process efficiency.In summary,this work systematically examines catalyst design principles and mechanistic insights in CO2 hydrogenation to olefins,critically evaluates the merits and limitations of different technical approaches,and proposes key areas for future investigation.With the growing emphasis on green chemistry and sustainable development,CO₂hydrogenation to olefins holds significant potential as a transformative technology for achieving carbon neutrality.