Design of catalysts for selective CO2 hydrogenation

CO2 hydrogenation with green hydrogen is a practical approach for the reduction of CO2 emissions and the generation of high-value-added chemicals. Generally, product selectivity is affected by the associated reaction mechanisms, internal catalyst identity and structure, and external reaction conditions. Here we examine typical CO2 hydrogenation reaction pathways, which can provide insight useful for the atomic-level design of catalysts. We discuss how catalyst chemical states, particle sizes, crystal facets, synergistic effects and unique structures can tune product selectivity. Different catalysts, such as Fe-, Co-, Ni-, Cu-, Ru-, Rh-, Pd-based and bifunctional structured catalysts, and their influence on CO2 hydrogenation products (such as CO, methane, methanol, ethanol and light olefins) are discussed. Beyond catalyst design, emerging catalytic reaction engineering methods for assisting the tuning of product selectivity are also discussed. Future challenges and perspectives in this field are explored to inspire the design of next-generation selective CO2 hydrogenation processes to facilitate the transition towards carbon neutrality. CO2 hydrogenation is promising for the conversion of waste CO2 emissions into value-added chemicals. This Review examines the atomic-level design of heterogeneous catalysts with precise active sites and related catalytic reaction engineering for tuning CO2 hydrogenation selectivity.