PdBi/C electrocatalysts for ethanol electro-oxidation in alkaline medium

PdBi/C electrocatalysts (Pd:Bi atomic ratios of 95:05, 90:10, 80:20 and 70:30) were prepared by borohydride reduction using Pd(NO3)2.2H2O and Bi(NO3)3.5H2O as metal sources and Vulcan XC72 as support. The electrocatalysts were characterized by energy-dispersive X-ray analysis, X-ray diffraction, transmission electron microscopy and cyclic voltammetry. The activity for the ethanol electro-oxidation in alkaline medium was investigated at room temperature by chronoamperometry and the results were compared with Pt/C and PtBi/C electrocatalysts. PdBi/C (95:05) electrocatalyst showed a significant increase of performance for ethanol electro-oxidation compared to Pd/C and others PdBi/C electrocatalysts. The final current value after holding the cell at −0.4 V versus Ag/AgCl electrode for 30 min in alkaline medium for PdBi/C (95:05) electrocatalyst was about eleven times higher than the current value of the Pt/C electrocatalyst and 1.5 times higher than PtBi/C (50:50).

► PdBi/C electrocatalysts (Pd:Bi atomic ratios of 95:05, 90:10, 80:20 and 70:30) were prepared by borohydride reduction.
► PdBi/C (95:05) electrocatalyst showed an increase of performance for ethanol oxidation in alkaline medium compared to Pd/C.
► The high activity of PdBi/C could be related to the removal of the intermediates by the OHad species.