Development of catalysts and reactor designs for CO2 electroreduction towards C2+ products

Recent research on the electrocatalytic CO2 reduction reaction (eCO2RR) has garnered significant attention given its capability to address environmental issues associated with CO2 emissions while harnessing clean energy to produce high-value-added products. Compared to C1 products, C2+ products provide greater energy densities and are highly sought after as chemical feedstocks. However, the formation of the C-C bond is challenging due to competition with the formation of H-H and C-H bonds. Therefore, to elevate the selectivity and yield of C2+ fuels, it is essential to develop more advanced electrocatalysts and optimize the design of electrochemical cell configurations. Of the materials investigated for CO2RR, Cu-based materials stand out due to their wide availability, affordability, and environmental compatibility. Moreover, Cu-based catalysts exhibit promising capabilities in CO2 adsorption and activation, facilitating the formation of C2+ compounds via C-C coupling. This review examines recent research on both electrocatalysts and electrochemical cells for CO2 electroreduction to C2+ compounds, introducing the core principles of eCO2RR and the reaction pathways involved in generating C2+ products. A key focus is the categorization of Cu-based catalyst designs, including defect engineering, surface modification, nanostructure engineering, and tandem catalysis. By analyzing recent studies on eCO2RR with Cu-based catalysts, we aim to elucidate the mechanisms behind enhanced selectivity for C2+ compounds. Additionally, various types of electrolytic cells are discussed. Lastly, the prospects and limitations of utilizing Cu-based materials and electrocatalytic cells for CO2 reduction are highlighted for future research.