A review of electroreduction of CO 2 to C 1 products: Catalysts design, characterizations and performance evaluation

The large-scale use of fossil fuels leads to the rising concentration of CO 2 in the atmosphere, which leads to serious environmental problem. In order to alleviate this problem, it is an effective way to convert CO 2 to C 1 (such as CO, CH 4 , CH 3 OH, formic acid and formate) as high value-added products, so as to make full use of carbon resources. Electrocatalytic CO 2 reduction (CO 2 RR) is the use of renewable energy to reduce CO 2 to valuable C 1 products by using CO 2 and H 2 O as raw materials. It has the advantages of low energy consumption, mild reaction conditions and no pollution, which has attracted wide attention in recent years. In this review, we firstly describe the basic principle, performance evaluation parameters and reaction devices of CO 2 RR, summarize the preparation methods of working electrodes, enumerate the types and application scenarios of commonly used electrolytes, as well as electrochemical test parameters and common product analysis methods. Then, we systematically summarize the research progress of CO 2 electroreduction catalysts, including the application of single -atom catalysts, dual -atom catalysts and nano -porous metal catalysts in CO 2 RR, overview the design, preparation and characterization methods of CO 2 electroreduction catalysts, and the structure and synthesis methods of various catalysts in detail. Finally, the C 1 products generated by CO 2 RR, such as CO, CH 4 , CH 3 OH, formic acid and formate, are discussed, and the effects of catalysts with different structures on the products selectivity are analyzed.