Robust and efficient electroreduction of CO$_2$ to CO in a modified zero-gap electrochemical cell

Excellent energy efficiency and system stability are critical factors guiding the practical application of carbon dioxide reduction reaction (CO$_2$RR ) systems. This work promotes reduction reaction kinetics in a modified zero-gap electrolyzer by regulating the operation temperature and pressure. The energy efficiency of the CO$_2$RR system is enhanced, such as 52.6 % at a current of 1.2 A under alkaline conditions and 49.4 % under neutral conditions, with the characteristics of low voltage and high Faradaic efficiency. In addition, the optimization of the reaction microenvironment effectively alleviates the precipitation issue, enabling the system to operate stably for more than 100 h, with a Faradaic efficiency of more than 90 % for CO generation. Engineering-integrated electrochemistry inspires the future development of CO$_2$RR technology.