Electrochemical investigations have been carried out to study the oxidation kinetics of ethanol in alkaline solution on carbon-supported ternary alloy catalysts PtÀPdÀAu within the temperature range of 20À80 °C. To derive a better understanding of the contribution of each of the metallic components toward the catalytic oxidation of ethanol, some of the investigations were extended to the individual noble metals for comparison, however, at a single temperature (20 °C). The individual metals could barely show their catalytic efficiency toward ethanol oxidations when compared to the alloyed catalyst. The ternary catalyst exhibited much lower values and a larger temperature dependence of onset potential for ethanol oxidation. With the rise of potential, the apparent activation energy (E a(app) ) for ethanol oxidation on the Pt/C electrode increased, whereas a decreasing trend was observed with the Pt 30 Pd 38 Au 32 /C electrode. It was suggested that the Pt 30 Pd 38 Au 32 /C electrode bears an excellent tolerance toward ethanolic residues, for the temperature range studied. In correlation with the results obtained from the above study, attempts were made to elucidate the oxidation reaction mechanism, and this further evoked interest in extending the work to the estimation of products formed during oxidation of ethanol within the same temperature range through ion chromatographic analysis. The pronounced increase in the quantity of oxidation products, such as acetate and carbonate, obtained over the ternary catalyst as compared to single Pt, substantiates the kinetic enhancement of ethanol oxidation, attributable to the cometal partnership between Pd and Au when incorporated in the Pt matrix. In summary, the multimetallic nanocrystallites can not only show their capability of extracting the best possible number of electrons from the alcohol fuel in alkaline solutions, harnessing more energy, but also, at the same time, bring down the cost of the catalyst material by reducing the Pt content to a considerable extent.

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The present article deals with the comprehensive electrocatalytic study of the binary and ternary combinations of Ni and Au with Pd for use as the anode component of a direct ethanol fuel cell (DEFC) operating with an anion-exchange membrane (AEM). The catalysts were grown on a carbon support by chemical reduction of the respective precursors. The information on surface morphology, structural characteristics, and bulk composition of the catalyst was obtained using transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. Brunauer–Emmett–Teller (BET) surface area and the pore widths of the catalyst particles were calculated by applying the BET equation to the adsorption isotherms. The electrochemical techniques like cyclic voltammetry, chronoamperometry, and impedance spectroscopy were employed to investigate the electrochemical parameters related to electro-oxidation of ethanol in alkaline pH on the catalyst surfaces within the temperature range 20–80 °C. The results show that the use of the ternary PdAuNi catalyst at the anode of an in-house fabricated DE(AEM)FC can increase the peak power density by more than 175% as compared with the use of the monometallic Pd catalyst, 108% as compared with the use of the bimetallic PdNi catalyst, and 42% as compared with the use of the bimetallic PdAu catalyst. The higher yield of the reaction products CH3CO2 – and CO3 2– on the PdAuNi catalyst compared to its single and binary counterparts in alkaline medium, as estimated by ion chromatography, further substantiates the catalytic superiority of the PdAuNi catalyst to a remarkable extent over the other catalysts studied.

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