LAUSR

Abstract Palladium and niobium in 1: 0, 3: 1, 2: 1 and 1: 1 carbon black electrocatalysts, respectively, were prepared by a chemical reduction method. The Pd1Nb1/C electrocatalyst showed a maximum power density of 27 mW cm−2 at 60 °C in the ethanol direct alkaline fuel cell (ADEFC) experiment. The residues of products formed in 60 °C of ADEFC operation were analyzed by FT-Raman and Pd1Nb1/C presented higher carbonate formation than the other products using the different electrocatalysts. In addition, the electrocatalysts of Pd1Nb1/C exhibited a more negative onset potential for both the CO stripping experiment and the ethanol oxidation reaction. Nb also increased the exchange current density by ethanol oxidation using the different electrocatalysts. We suggest that higher hydrophilicity, greater number of defects and oxygenated species promote bifunctional and electronic effects, improving the electrocatalytic activity of Pd. Therefore, Nb is an interesting co-catalyst for ADEFC Pd-based electrocatalysts.