Recent Development of Electrocatalytic CO2 Reduction Application to Energy Conversion.

Carbon dioxide (CO2 ) emission has caused greenhouse gas pollution worldwide. Hence, strengthening CO2 recycling is necessary. CO2 electroreduction reaction (CRR) is recognized as a promising approach to utilize waste CO2 . Electrocatalysts in the CRR process play a critical role in determining the selectivity and activity of CRR. Different types of electrocatalysts are introduced in this review: noble metals and their derived compounds, transition metals and their derived compounds, organic polymer, and carbon-based materials, as well as their major products, Faradaic efficiency, current density, and onset potential. Furthermore, this paper overviews the recent progress of the following two major applications of CRR according to the different energy conversion methods: electricity generation and formation of valuable carbonaceous products. Considering electricity generation devices, the electrochemical properties of metal-CO2 batteries, including Li-CO2 , Na-CO2 , Al-CO2 , and Zn-CO2 batteries, are mainly summarized. Finally, different pathways of CO2 electroreduction to carbon-based fuels is presented, and their reaction mechanisms are illustrated. This review provides a clear and innovative insight into the entire reaction process of CRR, guiding the new electrocatalysts design, state-of-the-art analysis technique application, and reaction system innovation.