Performance of carbon-supported palladium and palladiumruthenium catalysts for alkaline membrane direct ethanol fuel cells

• Pd/C and PdxRu/C nanoparticles are successfully prepared.
• The catalytic activity of samples is studied electrochemically.
• The samples are evaluated in alkaline direct ethanol fuel cells.
• Pd12Ru/C shows higher single cell activities than PtRu/C.

The activity of carbon supported palladium-based catalysts towards ethanol oxidation reaction in alkaline medium is investigated. To this end, Pd and PdxRu (x = 1, 6, 12) materials are synthesized supported on Vulcan XC72R by a modified impregnation method. These materials are characterized physicochemically and their composition varies between 40 and 50 wt. % of metal content. The mean size of nanoparticles is below 4 nm, and the size of the majority of particles ranges from 2 to 6 nm. The catalytic activity of these samples is also tested in half-cell and alkaline membrane direct ethanol fuel cell (AMDEFC). Lower onset potential and higher oxidation current densities is observed in palladium-rich bimetallic catalysts. By using the prepared samples as anode of AMDEFC and a commercial membrane of polybenzimidazole as solid electrolyte, the maximum power density is observed for Pd12Ru/C, 97 mW cm−2, almost doubling the value achieved by the catalyst Pd/C (50 mW cm−2), and above the obtained by commercial PtRu/C catalyst (89 mW cm−2).

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