Nickel oxide/nitrogen doped carbon nanofibers catalyst for methanol oxidation in alkaline media
By Al-Enizi, Abdullah M.; Ghanem, Mohamed A.; El-Zatahry, Ahmed A. & Al-Deyab, Salem S.
Published in Electrochimica Acta
2014
Abstract
Uniform and highly doped nitrogen carbon nanofibers (N-CNFs) have been produced by electrospinning of solution mixture that contains polyacrylonitrile, polyaniline and graphene and followed by annealing at 1200 °C. The NiO catalyst was loaded onto N-CNFs by chemical precipitation of Ni(OH)2 and treating at 400 °C. The physicochemical characterizations show that the N-CNFs have an average diameter of 250 nm with nitrogen-doping level of 17 wt. % and BET surface area of 440 m2 g-1. The NiO catalyst with particle size of 7.0 to 8.0 nm was uniformly loaded over the surface of the carbon nanofibers. The electrocatalytic activity of NiO/N-CNFs hybrid for methanol oxidation reaction in basic medium has been investigated by cyclic voltammetry and chronoamperometry techniques. The results show that the NiO/N-CNFs catalyst has superior specific and mass activities for methanol oxidation over the other nickel based catalysts. In addition negative shift in the methanol oxidation potential was observed which relies on the loading amount of NiO/N-CNFs catalyst. The highly doped nitrogen carbon nanofibers electrode based on polyacrylonitrile, polyaniline and graphene composite could be considered as a promising candidate to act as a catalyst support material.