Electrooxidation of Methanol and Ethanol on Electrodeposited Ni-MgO/C Nanocomposite Electrodes by Electrochemical Techniques

摘要

In this article, Ni-MgO nano-composites on carbon anodes have been prepared by electrodeposition technique from nickel Watts bath in the presence of MgO fine reinforcement particles. Their application as electrocatalysts for the oxidation of methanol and ethanol were investigated in alkaline medium and compared with that of carbon coated pure Ni (Ni/C). The chemical composition, phase structure and surface morphology of deposits were studied by energy dispersive X-ray spectroscopy (EDX), X-ray diffractometer (XRD) and scanning electron microscopy (SEM), respectively. Different electrochemical techniques were utilized to estimate the catalytic activity of the synthesized anodes such as cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS). Our findings demonstrate that Ni/C electrocatalyst alone exhibits remarkably low catalytic activity and poor stability toward the electrooxidation process. Inclusion of MgO significantly promotes the catalytic activity of the Ni catalyst for the alcohol electrooxidation and enhances its anti-poisoning ability. The results of EIS confirmed that of CVand reveal a lower charge transfer resistance and enhanced roughness for the Ni-MgO/C nano-composite electrodes compared with that of Ni/C.