Hybrid Cu and Cu as Atomic Interfaces Promote High-Selectivity Conversion of CO to C H OH at Low Potential.

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