Bridging Trans-Scale Electrode Engineering for Mass CO 2 Electrolysis.

Electrochemical CO 2 upgrade offers an artificial route for carbon recycling and neutralization, while its widespread implementation relies heavily on the simultaneous enhancement of mass transfer and reaction kinetics to achieve industrial conversion rates. Nevertheless, such a multiscale challenge calls for trans-scale electrode engineering. Herein, three scales are highlighted to disclose the key factors of CO 2 electrolysis, including triple-phase boundaries, reaction microenvironment, and catalytic surface coordination. Furthermore, the advanced types of electrolyzers with various electrode design strategies are surveyed and compared to guide the system architectures for continuous conversion. We further offer an outlook on challenges and opportunities for the grand-scale application of CO 2 electrolysis. Hence, this comprehensive Perspective bridges the gaps between electrode research and CO 2 electrolysis practices. It contributes to facilitating the mixed reaction and mass transfer process, ultimately enabling the on-site recycling of CO 2 emissions from industrial plants and achieving net negative emissions.