Hybrid Cu0 and Cux + as Atomic Interfaces Promote High-Selectivity Conversion of CO2 to C2 H5 OH at Low Potential.

Abstract

The mixing of charge states of metal copper catalysts may lead to a much improved reactivity and selectivity toward multicarbon products for CO2 reduction. Here, an electrocatalyst model composed of copper clusters supported on graphitic carbon nitride (g-C3 N4 ) is proposed; the connecting Cu atoms with g-C3 N4 can be oxidized to Cux + due to substantial charge transfer from Cu to N atoms, while others stay as Cu0 . It is revealed that CO2 can be captured and reduced into *CO on the Cut 0 site, owing to its zero oxidation state. More importantly, C-C coupling reaction of two *CHO species on the Cut 0 -Cub x + atomic interface can occur with a rather low kinetic barrier of 0.57 eV, leading to the formation of the final C2 product, namely, C2 H5 OH. During the whole process, the limiting potential is just 0.68 V. These findings may open a new avenue for CO2 reduction into high-value fuels and chemicals.