Rational design of carbon-based metal-free catalysts for electrochemical carbon dioxide reduction: A review

Electrochemical CO2 reduction to chemicals or fuels presents one of the most promising strategies for managing the global carbon balance, which yet poses a significant challenge due to lack of efficient and durable electrocatalyst as well as the understanding of the CO2 reduction reaction (CO2RR) mechanism. Benefiting from the large surface area, high electrical conductivity, and tunable structure, carbon-based metal-free materials (CMs) have been extensively studied as cost-effective electrocatalysts for CO2RR. The development of CMs with low cost, high activity and durability for CO2RR has been considered as one of the most active and competitive directions in electrochemistry and material science. In this review article, some up-to-date strategies in improving the CO2RR performance on CMs are summarized. Specifically, the approaches to optimize the adsorption of CO2RR intermediates, such as tuning the physical and electronic structure are introduced, which can enhance the electrocatalytic activity of CMs effectively. Finally, some design strategies are proposed to prepare CMs with high activity and selectivity for CO2RR. (C) 2019 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.