Electrochemical CO₂ reduction: Electrocatalyst, reaction mechanism, and process engineering

Highlights: • Review of recent development in CO₂ reduction electrocatalysts. • Recent advances in understanding reaction mechanism of CO₂ electroreduction. • Design and engineering challenges towards practical CO₂ electrolysis processes. Carbon dioxide (CO₂) emission from fossil fuel utilization poses a potential thread to global climate. Recent development in electrochemical CO₂ reduction opens up new possibilities of utilization of CO₂ as a carbon feedstock for fuel generation and commodity chemicals. This article reviewed progress related to electrochemical CO₂ reduction in the past few years, with a focus on new development of CO₂ reduction electrocatalysts, mechanistic understanding of CO₂ electro-reduction reaction, and process engineering efforts in CO₂ electrolyzers. Additionally, critical issues associated with current state-of-art systems were identified and potential directions for future studies were discussed. The article aims at providing the community a timely review of recent technical achievements as well as inspiring new ideas towards a practical CO₂ electrolysis technology.