Development of Pt and Pt–Fe Catalysts Supported on Multiwalled Carbon Nanotubes for Oxygen Reduction in Direct Methanol Fuel Cells

Abstract

and catalysts supported on multiwalled carbon nanotubes (MWCNTs) were prepared by impregnation and reduction at intermediate temperature . The MWCNTs with diameters ranging from 20 to were synthesized by a spray pyrolysis technique. and /MWCNT catalysts were characterized by X-ray diffraction, X-ray fluorescence, scanning electron microscope—energy dispersive X-ray analysis, and transmission electron microscopy techniques. The electrocatalytic behavior for the oxygen reduction reaction was investigated in rotating disk electrode configuration in an acidic medium, also in the presence of various methanol concentrations (0.01, 0.1, and ). An anodic shift of the peak potential for methanol oxidation of was observed in the presence of methanol concentration for the catalyst compared to the catalyst. Both materials were used as cathodes in a direct methanol fuel cell at 30 and . A better performance was obtained for the cell based on /MCWNTs as cathode catalyst. Although slight iron dissolution was observed after two weeks of discontinuous operation, the performance of the catalyst was larger than the catalyst.