Valorizing carbon dioxide via electrochemical reduction on gas-diffusion electrodes

The electrochemical carbon dioxide (CO2) reduction provides a means to upgrade CO2 into value-added chemicals. When powered by renewable electricity, CO2 electroreduction holds the promise of chemical manufacturing with carbon neutrality. A commercially relevant CO2 electroreduction process should be highly selective and productive toward desired products, energetically efficient for power conversion, and stable for long-term operation. To achieve these goals, designing gas-diffusion catalytic electrodes and prototyping reactors built upon in-depth understandings of the reaction mechanisms are of paramount importance. In this review, the fundamentals of gas-diffusion electrodes are briefly presented. Then, the most recent advances in developing high-performance CO2 reduction using gas-diffusion electrodes are overviewed. Reactor engineering aiming at enhancing productivity, energy efficiency, CO2 single-pass utilization, and operating lifetime is further discussed. Challenges in developing CO2 electroreduction systems are included. The prospects for advancing CO2 electroreduction toward practical applications are also narrated.