Selectivity regulation of CO₂ electroreduction on asymmetric AuAgCu tandem heterostructures

Rational design and synthesis of multimetallic nanostructures (NSs) are fundamentally important for electrochemical CO₂ reduction reaction (CO₂RR). Herein, a multi-step seed-mediated growth method is applied to synthesize asymmetric AuAgCu heterostructures using Au nanobipyramids as nucleation seeds, in which their composition and structures are well controlled. We find that the selectivity of C₂ products for CO₂RR could be effectively regulated by tandem catalysis and electronic effect over trimetallic AuAgCu heterostructures. Particularly, the Faraday efficiency toward ethanol could reach up to 37.5% at a potential of −0.8 V versus reversible hydrogen electrode over asymmetric Au₁Ag₁Cu₅ heterostructures with segregated domains of three constituent metals. This work provides an efficient strategy for the synthesis of multicomponent architectures to boost their promising application in CO₂RR.