Electrooxidation of methanol and ethanol on carbon electrodeposited Ni–MgO nanocomposite

Abstract

Ni–MgO nano-composites were prepared on carbon anodes by electrodeposition from a nickel Watts bath in the presence of fine MgO reinforcement particles. Their performance as electrocatalysts for the oxidation of methanol and ethanol in alkaline medium was investigated and compared with that of carbon coated pure Ni (Ni/C). The chemical composition, phase structure, and surface morphology of the deposited nano-composites were studied by energy dispersive X-ray spectroscopy, X-ray diffractometry, and scanning electron microscopy, respectively. Different electrochemical techniques were used to estimate the catalytic activity of the prepared electrocatalyst anodes, including cyclic voltammetry (CV), chronoamperometry, and electrochemical impedance spectroscopy (EIS). The Ni/C electrocatalyst alone exhibited remarkably low catalytic activity and poor stability toward the electrooxidation process. The inclusion of MgO significantly promoted the catalytic activity of the Ni catalyst for the alcohol electrooxidation and enhanced its poisoning resistance. The EIS results confirmed those of CV and revealed a lower charge transfer resistance and enhanced roughness for the Ni–MgO/C nano-composite electrodes compared with those of Ni/C.