Bismuth-doped cobaltosic oxide as a noble-metal free electrocatalyst for the efficient methanol oxidation reaction

Abstract

BackgroundMethanol electro-oxidation reactions (MOR) are utilized to provide electricity in direct methanol fuel cells (DMFC), which requires a reasonable design of catalysts to accelerate sluggish MOR. Herein, a series of cobalt oxides have been doped with a foreign oxophilic transition metal (Bi) by the sol-gel method and further calcination treatment. MethodsThe composition and structure of Bi0.13Co2.87O4-550 were characterized by the scanning electron microscopy (SEM), the powder X-ray diffraction (XRD), and X-ray photoelectron spectra (XPS). Evaluate the electrocatalytic performance of materials by cyclic voltammetry, chronoamperometry, and impedance spectroscopy. Significant findingsBy virtue of the tunable compositional and structural advantages, the optimized Bi0.13Co2.87O4-550 nanocomposite shows the excellent electrocatalytic activity, very high mass activity (808.5 mA mg−1), as well as remarkable durability to resist CO poisoning during methanol oxidation. The excellent electrocatalytic activity for MOR is attributed to the high specific surface area, abundant active sites and superior mass transportability. Furthermore, the oxidation of other alcohols including ethanol, ethylene glycol and glycerol are also realized by the electrocatalysis of Bi0.13Co2.87O4-550. This work provides a good idea for the design of non-precious metal electrocatalysts with the high performance.