Engineering Cu(I)/Cu(0) interfaces for efficient ethanol production from CO2 electroreduction

By leveraging a Cu(OH)F precursor, we construct a disk -like Cu(I)/ Cu(0) interface model (P-Cux/Cu2OF) composed of F -stabilized Cu(I) shell and Cu(0) core by one-step pulsed potential conversion. The interfacial region is shown to facilitate ethanol formation, guaranteeing a high FE(C2+) of up to 80.2%. Tuning the Cu(I)/Cu(0) ratio enhances the ethanol yield by 18.5 -fold over pure P -Cu, with the corresponding partial current density (jethanol) reaching up to 128 mA/cm2. This is enabled by a 3.6 -fold boost in selectivity for the ethanol product (35.4%) and an overall 7.8 -fold boost in activity (jC2+up to 288 mA/cm2). The interactions between P -Cu and Cu2OF upshift the d -band center of Cu sites on the interface region, which is critical to asymmetrical C -C coupling to form OCCOH*, concurrent with a lowered energy barrier for ethanol formation. On the other hand, the ethylene -forming symmetrical C -C coupling occurs primarily on P -Cu away from the Cu(I)/Cu(0) interface.