Selective adsorption of palladium complex for carbon-supported Pd/Mo electrocatalyst by the charge enhanced dry impregnation method

•The charge enhanced dry impregnation method was developed for electrocatalyst.•Palladium (II) was selectively adsorbed on MoO3 rather than carbon support.•Enhanced electrocatalytic performance was achieved.

According to the different point of zero charge (PZC) of MoO3 and carbon black (XC72R), an efficient method for preparing highly dispersed carbon-supported Pd/Mo bimetallic nanoparticles is described. The charge enhanced dry impregnation (CEDI) technique is developed for the preparation of Pd/Mo/C electrocatalysts by selectively driving the [Pd(NH3)4]2+ cations onto MoO3 phase instead of carbon support. The CEDI method could minimize the migration of Pd away from the MoO3 phase to carbon support during reduction up to 400 °C. Oxygen reduction measurements by linear sweep voltammetry indicate the carbon-supported Pd/Mo catalyst prepared by the CEDI method has better catalytic activity than that prepared with the dry impregnation method as the CEDI method gives strong interactions between Pd and Mo.