ABSTRACT The electrocatalytic activity of oxophilic Ag nanoparticles, combined with low Pd and Au loading, was investigated for ethanol electrooxidation reactions (EOR) and glycerol electrooxidation reactions (GOR) in alkaline medium. The EOR and GOR results revealed competitive current densities and less positive onset potentials for the AgPd/C and AgPdAu/C electrocatalysts—both containing 5 wt% Pd—compared to the commercial Pd/C catalyst, which has a significantly higher loading of the costly noble metal (20 wt%). In situ FTIR analyses during EOR confirmed that ethanol is initially adsorbed as acetyl species (CH 3 CO ads ), which are subsequently oxidized to acetate ions, the main stable product in alkaline medium. During GOR, the in situ FTIR studies demonstrated that catalyst composition influences the oxidation pathways: Pd‐rich surfaces favor oxalate formation, while a significant presence of Ag promotes deeper oxidation (up to carbonate), with the AgPdAu/C ternary catalyst exhibiting intermediate behavior. One key benefit is Ag's lower susceptibility to irreversible adsorption of reaction byproducts, which enhances electrocatalyst durability. Thus, surface segregation of Ag at high potentials can modify the catalytic surface reactivity, influencing both stability and activity.
Gentil et al. (Thu,) studied this question.