Recent Advances in Electrochemical, Photochemical, and Photoelectrochemical Reduction of CO2 to C2+ Products

Environmental problems such as global warming are one of the most prominent global challenges. Researchers are investigating various methods for decreasing CO2 emissions. The CO2 reduction reaction via electrochemical, photochemical, and photoelectrochemical processes has been a popular research topic because the energy it requires can be sourced from renewable sources. The CO2 reduction reaction converts stable CO2 molecules into useful products such as CO, CH4, C2H4, and C2H5OH. To obtain economic benefits from these products, it is important to convert them into hydrocarbons above C-2. Numerous investigations have demonstrated the uniqueness of the C-C coupling reaction of Cu-based catalysts for the conversion of CO2 into useful hydrocarbons above C-2 for electrocatalysis. Herein, the principle of semiconductors for photocatalysis is briefly introduced, followed by a description of the obstacles for C2+ production. This review presents an overview of the mechanism of hydrocarbon formation above C-2, along with advances in the improvement, direction, and comprehension of the CO2 reduction reaction via electrochemical, photochemical, and photoelectrochemical processes.