Role of the Metal‐Oxide Support in the Catalytic Activity of Pd Nanoparticles for Ethanol Electrooxidation in Alkaline Media

Abstract The promotional role of oxide supports (CeO 2 , SnO 2 , TiO 2 ) on ethanol electrooxidation in alkaline media over Pd nanoparticles (NPs) is presented and compared to Pd on carbon. XPS revealed a shift to lower binding energy of the Pd 3d peak when Pd NPs were deposited on metal oxides, implying a charge transfer from the oxides to the Pd. The catalytic activity of the supported NPs for ethanol electrooxidation was assessed by using cyclic voltammetry and chronoamperometry. The electrooxidation products were monitored in situ, using polarization modulation–infrared reflection absorption spectroscopy (PM‐IRRAS), which revealed that the supports influence the selectivity of reactions on Pd. Pd/CeO 2 has superior selectivity towards breaking the C−C bond to produce CO 2 compared to the other three supports. Acetate, as a product, was evident on all of the catalysts, but at different ratios. Pd supported on metal oxides showed higher activity and, in particular, CeO 2 and SnO 2 stand out as the best supports.