CO₂ reduction to acetate in mixtures of ultrasmall (Cu) n ,(Ag) m bimetallic nanoparticles

Monodispersed mixtures of 6-nm Cu and Ag nanoparticles were prepared by electrochemical reduction on electrochemically polymerized poly-Fe(vbpy)₃(PF₆)₂ film electrodes on glassy carbon. Conversion of the complex to poly-Fe(vbpy)₂(CN)₂ followed by surface binding of salts of the cations and electrochemical reduction gave a mixture of chemically distinct clusters on the surface, (Cu) m ,(Ag) n |polymer|glassy carbon electrode (GCE), as shown by X-ray photoelectron spectroscopy (XPS) measurements. A (Cu)₂, (Ag)₃|(80-monolayer-poly-Fe(vbpy)₃2+|GCE electrode at −1.33 V vs. reversible hydrogen electrode (RHE) in 0.5 M KHCO₃, with 8 ppm added benzotriazole (BTA) at 0 °C, gave acetate with a faradaic efficiency of 21.2%.