Composition-Dependent Ethanol Electrooxidation Activity of CuAuPd Alloy Nanoparticles Prepared by an Ionic Liquid/Metal Sputtering Technique

Ternary CuAuPd alloy nanoparticles (NPs) were synthesized via the simultaneous sputtering of Cu, Au, and Pd onto a room-temperature ionic liquid (RTIL) without additional stabilizing agents. The composition of the CuAuPd NPs was controlled by varying the surface area ratios of Cu, Au, and Pd sputtering target plates. The NPs were loaded on carbon black (CB) powders to obtain CuAuPd/CB electrocatalysts, by heating the RTIL containing NPs in the presence of CB powders. The electrocatalytic activity of CuAuPd/CB for ethanol oxidation reaction (EOR) was strongly dependent on alloy composition of NPs loaded. Although the highest mass activity observed for Cu32Au41Pd27 NPs was 6% higher than that of Au59Pd41/CB catalyst, the incorporation of Cu into AuPd alloy successfully caused a negative shift of approximately 0.1 V in the onset potential relative to AuPd/CB, indicating that the EOR proceeds more efficiently on CuAuPd/CB catalysts.