Investigation of a Pt–Fe/C catalyst for oxygen reduction reaction in direct ethanol fuel cells

Abstract

Three cathode catalysts (60% Pt/C, 30%Pt/C and 60% Pt–Fe/C), with a particle size of about2–3 nm, were prepared to investigate the effect ofethanol cross-over on cathode surfaces. All sampleswere studied in terms of structure and morphology byusing X-ray diffraction (XRD) and transmissionelectron microscopy (TEM) analyses. Their electrocatalyticbehavior in terms of oxygen reductionreaction (ORR) was investigated and compared usinga rotating disk electrode (RDE). The tolerance ofcathode catalysts in the presence of ethanol wasevaluated. The Pt–Fe/C catalyst showed both higherORR activity and tolerance to ethanol cross-over thanPt/C catalysts. Moreover, the more promising catalystswere tested in 5 cm2 DEFC single cells at 60and 80 C. An improvement in single cell performancewas observed in the presence of the Pt–Fecatalyst, due to an enhancement in the oxygenreduction kinetics. The maximum power densitywas 53 mW cm-2 at 2 bar rel. cathode pressure and80 C.