Copper-indium hybrid derived from indium-based metal-organic frameworks grown on oxidized copper foils promotes the efficient electroreduction of CO2 to CO

This work reports a novel and effective method for the preparation of the copper-indium bimetallic electrocatalysts by the in situ growth of indium-based metal organic frameworks on oxidized copper foils as the precursor. Compared with the oxide-derived copper and the copper-based carbon material derivative grown in situ on oxidized copper foils, the as-prepared copper-indium electrocatalyst with a self-supporting structure, high roughness factor and rich lattice defects exhibits a superior CO Faradaic efficiency of 95% and good stability for the 36-h potentiostatic test at -0.6 V versus a reversible hydrogen electrode. Density functional theory calculations indicated that the indium atoms occupying the surface copper vacancy defects show lower free energy needed for the formation of *COOH and more difficult desorption of *H than indium atoms, supported on the perfect copper surface. Thereby, the copper-indium catalyst promotes CO2 electroreduction to CO and strongly inhibits hydrogen evolution.

Automated summary

This study presents a novel method for synthesizing copper-indium bimetallic electrocatalysts with high CO Faradaic efficiency and stability on oxidized copper foils. Density functional theory calculations reveal that indium atoms occupying surface copper vacancy defects facilitate CO2 electroreduction to CO.