Electrochemical Characterization of Synthesized Ni–Co and Ni–Co–Fe Electrodes for Methanol Fuel Cell

Abstract

Pt based materials having high electrocatalytic properties are normally used for the electrodes of the fuel cell. But the cost of the material limits the commercialization of alcoholic fuel cell. Non-Pt based metals and alloys as electrode materials for methyl alcohol fuel cells have been investigated with an aim of finding high electrocatalytic surface property for the faster electrode reactions. Electrodes were fabricated by electrodeposition on pure Al foil, from an electrolyte of Ni, Co, and Fe salts. The optimum condition of electrodeposition was found by a series of experiments, varying the chemistry of the electrolyte, pH, temperature, current, and cell potential. Polarization study of the coated Ni–Co or Ni–Co–Fe alloy on pure Al was found to exhibit high exchange current density, indicating an improved electrocatalytic surface with faster charge–discharge reactions at anode and cathode and low overvoltage. Electrochemical impedance studies on the coated and uncoated surface clearly showed that the polarization resistance and impedance were decreased by Ni–Co or N–Co–Fe coating. X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), and atomic absorption spectroscopy (AAS) studies confirmed the presence of alloying elements and constituents of the alloy. The morphology of the deposits from scanning electron microscope (SEM) images indicated that the electrode surface was a three-dimensional space which increased the effective surface area for the electrode reactions to take place.