Electroreduction　of　CO　to　generate　fuels　and　chemicals　containing　multiple　carbon-atoms　holds　significant　potential　for　sustainable　chemical　production　and　intermittent　energy　storage.　Regulating　the　atomic-structure　of　catalytic-sites　during　the　CO　reduction　is　critical　for　achieving　enhanced　catalytic　performance　towards　the　desired　products.　Here,　we　introduce　Pb,　a　metal　with　a　vastly　different　in　atomic-size　and　immiscible　with　Cu,　to　form　the　Cu[sbnd]Pb　interface　during　CO　reduction.　The　incorporation　of　Pb　with　precisely　controlled　size/morphology　proves　effective　in　forming　the　desired　Cu[sbnd]Pb　heterostructure.　Consequently,　the　CuPb　catalyst　composite　achieves　a　remarkably　high　Faradaic　efficiency　exceeding　45　%　for　ethanol　at　−0.71　V　versus　the　reversible　hydrogen　electrode,　with　a　practical　relevant　ethanol　partial　current　density　of　over　220　mA　cm−2.　In　contrast,　the　pristine　Cu　only　exhibits　a　low　selectivity　of　approximately　20　%　towards　ethanol　under　identical　conditions.　Detailed　kinetic　analysis,　in-situ　X-ray　absorption　spectroscopy,　attenuated　total　reflectance　infrared　absorption　spectroscopy,　CO/Ar　co-feeding　and　CO　stripping　assessments　suggest　that　the　formation　of　Cu[sbnd]Pb　interface　substantially　reduces　the　CO　binding　affinity　on　Cu-catalytic　sites,　consequently　stirring　the　CO　reduction　pathway　towards　ethanol　rather　than　ethylene.　Our　work　showcases　an　effective　approach　for　steering　the　product　selectivity　between　ethylene　and　ethanol　during　electroreduction　of　CO.　©　2025　Elsevier　B.V.