Enhanced Electrocatalytic Activity of Ethanol Oxidation Reaction on Palladium-Silver Nanoparticles via Removable Surface Ligands.

This work developed a facile colloidal route to synthesize BH4 - -capped Pdx Agy nanoparticles (NPs) in water using the reducing ionic liquids of [Cn mim]BH4 , and the resulting NPs were prone to form the nanocomposites with [amim]+ -modified reduced graphene (RG). The removal of the metal-free inorganic ions of BH4 - can create the profoundly exposed interfaces on the Pdx Agy NPs during the electrooxidation, and favor the ethanol oxidation reaction (EOR) in lowering energy barrier. The counterions of [Cn mim]+ can gather ethanol, OH- ions, and the reaction intermediates on catalysts, and synergistically interact with RG to facilitate the charge transfer in nanocomposites. The interface-modified RG nanosheets can effectively segregate the Pdx Agy NPs from aggregation during the EOR. Along with the small size of 4.7 nm, the high alloying degree of 60.2%, the large electrochemical active surface area of 64.1 m2 g-1 , and the great peak current density of 1501 mA cm-2 mg-1 , Pd1 Ag2 @[C2 mim]BH4 -amimRG nanocomposite exhibits the low oxidation potentials, strong poison resistance, and stable catalytic activity for EOR in alkaline media, and hence can be employed as a promising anodic catalyst in ethanol fuel cells.