Recent Advances in Electrochemical, Photochemical, and Photoelectrochemical Reduction of CO 2 to C 2+ Products.

Environmental problems such as global warming are one of the most prominent global challenges. Researchers are investigating various methods for decreasing CO 2 emissions. The CO 2 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 CO 2 reduction reaction converts stable CO 2 molecules into useful products such as CO, CH 4 , C 2 H 4 , and C 2 H 5 OH. 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 CO 2 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 C 2+ 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 CO 2 reduction reaction via electrochemical, photochemical, and photoelectrochemical processes.