Breaking the kinetic limitation of formaldehyde oxidation by Ag-doping modulation of *H adsorption on Cu2O.

Ag-doped Cu2O nanosheets boost the electrocatalytic formaldehyde oxidation reaction (FOR), enabling co-production of hydrogen and formate. Coupling the FOR with the HER achieves dual hydrogen production, reducing system energy needs by 87% versus conventional water splitting. In situ studies confirm that Ag doping improves conductivity and promotes active hydrogen adsorption, guiding future FOR catalyst design.