Regulating Interfacial Hydrogen-Bonding Networks by Implanting Cu Sites with Perfluorooctane to Accelerate CO2 Electroreduction to Ethanol.

Abstract

Efficient CO2 electroreduction (CO2RR) to ethanol holds promise to generate value-added chemicals and harness renewable energy simultaneously. Yet, it remains an ongoing challenge due to the competition with thermodynamically more preferred ethylene production. Herein, we presented a CO2 reduction predilection switch from ethylene to ethanol (ethanol-to-ethylene ratio of ~5.4) by inherently implanting Cu sites with perfluorooctane to create interfacial non-covalent interactions. The 1.83%F-Cu2O organic-inorganic hybrids (OIHs) exhibited an extraordinary ethanol faradaic efficiency (FEethanol) of ∼55.2%, with an impressive ethanol partial current density of 166 mA cm-2 and excellent robustness over 60 hours of continuous operation. This exceptional performance ranks our 1.83%F-Cu2O OIHs among the best-performing ethanol-oriented CO2RR electrocatalysts. Our findings identified that C8F18 could strengthen the interfacial hydrogen bonding connectivity, which consequently promotes the generation of active hydrogen species and preferentially favors the hydrogenation of *CHCOH to *CHCHOH, thus switching the reaction from ethylene-preferred to ethanol-oriented. The presented investigations highlight opportunities for using noncovalent interactions to tune the selectivity of CO2 electroreduction to ethanol, bringing it closer to practical implementation requirements.