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

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.