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.