Modulation of *CHO Adsorption to Facilitate Electrocatalytic Reduction of CO to CH over Cu-Based Catalysts.

Copper (Cu) can efficiently catalyze the electrochemical CO reduction reaction (CORR) to produce value-added fuels and chemicals, among which methane (CH) has drawn attention due to its high mass energy density. However, the linear scaling relationship between the adsorption energies of *CO and *CHO on Cu restricts the selectivity toward CH. Alloying a secondary metal in Cu provides a new freedom to break the linear scaling relationship, thus regulating the product distribution. This paper describes a controllable electrodeposition approach to alloying Cu with oxophilic metal (M) to steer the reaction pathway toward CH. The optimized LaCu electrocatalyst exhibits a CH Faradaic efficiency of 64.5%, with the partial current density of 193.5 mA cm. The introduction of oxophilic La could lower the energy barrier for *CO hydrogenation to *CHO by strengthening the M-O bond, which would also promote the breakage of the C-O bond in *CHO for the formation of CH. This work provides a new avenue for the design of Cu-based electrocatalysts to achieve high selectivity in CORR through the modulation of the adsorption behaviors of key intermediates.