Electro-oxidation competency of palladium nanocatalysts over ceria-carbon composite supports during alkaline ethylene glycol oxidationElectronic supplementary information (ESI) available: Additional TEM micrographs and EDS mapping of the composite support and the prepared catalysts, surface features (XPS) of the as-prepared catalysts, cyclic stability of Pd-CeO2 (1 : 1) catalysts and behavior of catalysts in varying alkaline concentrations. See DOI: 10.1039/c8cy02232a

• Main Authors: Sankar, Sasidharan, Watanabe, Naoto, Anilkumar, Gopinathan M, Nair, Balagopal N, Sivakamiammal, Sailaja G, Tamaki, Takanori, Yamaguchi, Takeo
• Format: Article
• Language: English
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/c8cy02232a

Direct alcohol fuel cells (DAFCs) are widely regarded as one of the most promising among the futuristic and capable energy systems; direct liquid fuel cells (DLFCs). In this article, we discuss in detail the competency of palladium nanoparticles developed over carbon-ceria composite supports (Pd/C-CeO 2 ) as efficient and durable anode catalysts for the alkaline electro-oxidation of ethylene glycol (EGOR). For the first time, a systematic assessment of the EGOR performance of palladium catalysts with varying Pd-ceria ratios has been reported. The scalable solid-solution route reduction technique enabled the processing of Pd nanoparticles with controlled morphology, size and excellent CeO 2 interaction. The structural features of the prepared catalysts were studied using X-ray diffraction, electron microscopy (TEM) and X-ray photon spectroscopy techniques, while the electrochemical performance of the catalysts was analyzed using cyclic voltammetry and chronoamperometry. During alkaline EGOR, the Pd/C-CeO 2 catalysts showed an enhanced current density (as high as 68.5 mA cm −2 ), more negative onset potential, excellent mass activity (4.6 A mg −1 Pd ) and exceptional durability compared to Pd/C. The enhanced alkaline EGOR kinetics of the Pd/C-CeO 2 catalysts is well attributed to the promotion effect of CeO 2 on Pd by creating more Pd-OH ads and also improved tolerance to poisoning species on the Pd surface. Further, the enhanced ECSA of Pd/C-CeO 2 has also aided the excellent EGOR activity in alkaline medium. The validated enhanced oxidation ability of these Pd/C-CeO 2 catalysts for the anodic oxidation of other low molecular weight alcohol fuels including methanol and ethanol showcased their application potential toward DMFCs and DEFCs. The effect of varying Pd-CeO 2 ratios on the oxidation efficiency of ethylene glycol and low molecular weight alcohols in alkaline medium.