Electro-catalytic activity enhancement of Pd-Ni electrocatalysts for the ethanol electro-oxidation in alkaline medium: The promotional effect of CeO2 addition

► 5 wt.% of CeO2 addition can promote the formation of surface alloy and amorphous NiO of the PdNi/C. ► The surface alloy and NiO can provide an oxygen source for CO oxidation and accelerate the EOR. ► Excessive CeO2 results in the alternation of surface condition, deteriorating EOR performance.