MnO2–NiO–MWCNTs nanocomposite as a catalyst for methanol and ethanol electrooxidation

Abstract

The potential of metal oxide-based nanocatalysts and multi-walled carbon nanotubes (MWCNTs) for the methanol and ethanol electrooxidation process is studied in the attempt of introducing cheap and stable nanocatalysts for use in the alcohol oxidation process. In this regard MnO2–NiO (MN), and MnO2–NiO–MWCNT (MNM) are synthesized and characterized in terms of structure and morphology. The electrocatalytic activity of these materials is evaluated by electrochemical tests. MNM show 90% cyclic stability after 1000 consecutive cycles in methanol oxidation reaction (MOR) and 86% in ethanol oxidation reaction (EOR) and maximum current densities of 262 and 148 μA cm−2 in methanol and ethanol electrooxidation, in optimal scan rate respectively. Also, the onset potential of MNM is lower than MN, indicating superior kinetics and facile oxidation of methanol due to the synergistic effect of adding MWCNTs to the structure of MN nanocatalyst. From these results, MNM can be an attractive and inexpensive option for use in MOR and EOR process for application in alcohol fuel cells.