Selective hydrocarbon or oxygenate production in CO₂ electroreduction over metallurgical alloy catalysts

Alloying of metals can be used to optimize intermediate binding during electrocatalysis but challenges remain in overcoming thermodynamic atomic miscibility in alloys. Here we report a coordination-controlled metal alloy in which copper clusters are spatially dispersed in a crystalline silver lattice to promote the electrochemical reduction of CO2 to ethanol. The synergistic interactions between Cu-Cu sites and Cu-Ag interfaces achieve highly selective hydrocarbon and oxygenate production by strengthening and diversifying the binding of *CO intermediates on terrace and defect sites. To control atomic coordinates beyond the miscibility limit and optimize the catalyst microstructure, sacrificial elements are incorporated with thermodynamically guided compositions to form intermetallic compounds. The sacrificial elements are then selectively dealloyed. Using a membrane electrode assembly, ethylene-selective production on copper catalysts (Faradaic efficiency, 69.6 +/- 1.3%; full cell efficiency, 23.5%) is steered to ethanol-selective production on the supersaturated Ag-Cu solid-solution catalyst (Faradaic efficiency, 40.4 +/- 2.4%; full cell efficiency, 14.4%). Metallurgy-designed catalyst fabrication enables the efficient chemical manufacturing of either hydrocarbons or oxygenates and offers guidelines for catalyst design principles.