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 C–C bond challenge 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 to 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.