Eiectrocatalytic Oxidation of Methanol, Ethanol and Hydrogen Peroxide on the Nickel deposited Activated Carbon Electrode for Alkaline Fuel Cells

摘要

In our work we present our study on electrochemical oxidation of methanol, ethanol and hydrogen peroxide in alkaline solution with an eiectrocatalytic system composed of glassy carbon electrode coated with activated carbon supported Nickel. In Figure 1 the first cycle a pair of redox peaks appearing at 242 and 383 mV/SCE was assigned to Ni~(2+)/Ni~(3+) redox couple in alkaline media recorded at a potential sweep rate of 100mVs~(-1). The Ni/AC acts as a catalyst for the oxidation of methanol, ethanol and hydrogen peroxide in 2M KOH solution. The Ni/AC catalyst was characterized by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and scanning (SEM) and transmittance electron microscopy (TEM). Cyclic voltammetric experiments showed that all the liquid fuels can be oxidized at the surface of Ni/AC electrode. According to CV measurements the hydrogen peroxide oxidation is 4.2 and 3.1 times higher than that of methanol and ethanol oxidation. Preliminary tests on a single cell of a direct peroxide/peroxide fuel cell (DPPFC), direct methanol /peroxide fuel cell (DMPFC) and direct ethanol /peroxide fuel cell (DEPFC) indicate that DPPFC with the power density of 3.3 mW cm~(-2) provides higher performance as shown in Figure 2.