Electrocatalytic oxidation of ethanol at Pd/Ag nanodendrites prepared via low support electrodeposition and galvanic replacement

The electrodeposition of silver nanodendritic structures in the absence of supporting electrolyte is reported. The as-fabricated dendritic Ag causes an enhancement in Raman scattering of rhodamine B. The galvanic replacement of as-deposited silver with Pd resulted in the formation of dendritic Pd/Ag with a different morphology from the initial Ag dendrites. Scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), X-ray diffraction (XRD), and inductively coupled plasma mass spectrometer (ICP-MAS) revealed that the resulting product was composed of partially depleted Ag dendrites covered with Pd seeds. When employed as an electrocatalyst for ethanol oxidation in alkaline media, the Pd/Ag dendrite electrode exhibited remarkable activity with an onset potential of -0.60 V (vs. NHE) and j(b)/j(f) (backward current density/forward current density) of 0.49.