Co/CeO2-decorated carbon nanofibers as effective non-precious electro-catalyst for fuel cells application in alkaline medium

Abstract

In this study, Co/CeO2 decorated carbon nanofibers are introduced as effective electro-catalyst for methanol oxidation. Poly(vinyl alcohol) was used as carbon source due to its high carbon content characteristic as compared to many others polymer precursors for CNFs synthesis. Preparation of the introduced nanofibers could be achieved by calcination of electrospun nanofibers composed of cerium (III) acetate hydrate, cobalt (II) acetate tetra hydrate and poly(vinyl alcohol) in nitrogen environment at 700 °C. The produced sintered powder was characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HR-TEM), field-emission scanning electron microscopy (FESEM) equipped with rapid EDX (energy dispersive analysis of X-ray). The invoked characterization techniques indicated that the obtained material is carbon nanofibers decorated by Co/CeO2 nanoparticles. Investigation of the electrocatalytic activity of the introduced decorated nanofibers toward methanol oxidation indicated good performance as the corresponding current density increased with increasing methanol content in the alkaline medium. Interestingly, the introduced catalyst revealed negative onset potential (-50 mV vs. Ag/AgCl) which is a superior value among the reported non-precious electrocatalyst. Moreover, methanol oxidation takes place at relatively low applied voltage (180 mV vs. Ag/AgCl) which adds additional advantage for the introduced material. Overall, the introduced study opens new avenue for cheap and effective transition and rare earth family-based nanomaterials as non-precious catalyst for fuel cell application.