System Macro‐Modulation of Electrocatalytic CO 2 Reduction Beyond Catalyst Micro‐Design: Recent Advances, Challenges, and Perspectives

Abstract The clean‐energy‐powered electrochemical CO 2 reduction (CO 2 RR) to high‐value fuels holds great potential to realize a carbon‐neutral footprint. Tremendous progress is achieved in the past decades to clarify the underlying intrinsic relationships between various effects of catalysts and CO 2 RR performance from a micro‐level perspective. However, numerous studies indicate that all parts of electrocatalytic system construction will affect CO 2 RR performance, and closely relate to the ultimate industrial applications. To comprehensively cognize CO 2 RR, this review thus ventures to bridge this lacuna via casting a particular spotlight on this topic with a more comprehensive and in‐depth discussion. Taking holistic insights, beyond the micro‐level catalyst design, into the macro‐level components and system constructions toward CO 2 RR (e.g., electrolyzer design, electrode assembly, electrolyte, and membrane selection), with an emphasis on discussing their merits and drawbacks, applicable environments, encountered difficulties, and challenges, to identify their feasible applications, and understanding their inherent connections between each other, as well as their intrinsic relationships with CO 2 RR performance. It is sincere hope to provide holistic insights into understanding the myriad macro‐level components and their effects for CO 2 RR and further developing high‐performance energy storage and conversion devices.