Pressure‐Boosted C–C Coupling for CO₂ Electroreduction to Ethanol over the Cascade Sites of Cu Single‐Atom and Cu Cluster

Abstract Tandem catalysis of the CO₂ electroreduction reaction (CO₂RR) offers a promising way to obtain multicarbon products (C₂₊) with high Faradaic efficiency (FE). However, the synchronously changed CO supply and consumption with potentials and the mismatch between the two potential windows of the different components in tandem catalysts impede further understanding and development of tandem catalysis. Herein, a novel strategy of pressure regulating to separately promote the CO supply and consumption is reported on the cascade sites of Cu single‐atom and Cu cluster, where a near‐linear relationship between CO₂ pressure, CO supply, and ethanol FE is well established. Benefiting from the above strategy, the ethanol FE of 41.2% is achieved under 26 bar CO₂, which increases by ≈3 times that under ambient pressure. This work provides a new method of CO supply regulation and gives more mechanism insights into the tandem catalysis of CO₂ electroreduction toward multicarbon products.