Electrocatalytic CO2 reduction to syngas

Abstract

While carbon dioxide (CO2) is a major greenhouse gas, it is also an important C1 resource. In the trend of energy conservation and emission reduction, electrocatalytic reduction has become a very promising strategy for CO2 utilization because it can convert CO2 directly to high-valued chemicals and fuels under mild conditions. In particular, the product CO and by-product H2 can be combined into syngas by an electrocatalytic CO2 reduction reaction (CO2RR) in an aqueous medium. Different molar ratios of CO and H2 may be used to produce essential bulk chemicals or liquid fuels such as methanol, alkanes, and olefins through thermochemical catalysis, Fischer–Tropsch synthesis, microbial fermentation, and other techniques. This work discusses the latest strategies in controlling the molar ratio of CO/H2 and improving the yield of CO2RR-to-syngas. The challenges of electrocatalytic syngas production are analyzed from an industrial application perspective, and the possible measures to overcome them are proposed in terms of new catalyst design, electrolyte innovation, flow reactor optimization, anodic reaction coupling, and operando technique application.