Ultrafine Pd ensembles anchored-Au2Cu aerogels boost ethanol electrooxidation

Abstract Modification of the noble metal-based aerogels from the atomic scale is rarely being investigated despite the rapid development of various metallic aerogels. Recent studies have verified that Pd ensembles are more effective than isolated Pd atoms toward electrooxidation of ethanol. However, the electrocatalytic efficiency is still insufficient. Here, for the first time, we successfully anchored Pd-ensembles on the surface of Au2Cu metallic hydrogels via kinetically controlled galvanic displacement reaction. The atomic configuration optimized Au2Cu@Pd metallic aerogels exhibited significantly enhanced mass activity ~ 11.6 times of commercial Pd and excellent stability with remained 90% of mass activity after 300 potential cycle test. The ligand effect and geometric effect generated by the finely tailored atomic configurations including Pd ensembles and core-shell structure are critical for enhancing electrocatalytic efficiencies. Thus, the Pd ensembles anchored-Au2Cu aerogels hold a great promise for being potentially applied in devices such as direct alcohol fuel cells, biosensors and electronics.