Effect of surface oxygen complexes of sugar charcoal on the half cell potential of carbon-nickel ferrite electrodes

Abstract

Carbon-nickel ferrite electrodes were prepared by pressing equal amounts of charcoals and nickel ferrite using ABS polymer (in acetone + benzene) as binder on a steel mesh. The half cell potentials reported were measured with reference to saturated calomel electrode. The electrolyte used was 4-N potassium hydroxide and fuel used was methanol. The surface oxygen complexes on the charcoals were varied (i) by heat-treating the sugar charcoal in vacuum at 400, 750 and 1000° C and (ii) by boiling in 4N.HNO3 for different intervals of time. Half cell potential measured increases with the increase of oxygen content of the charcoals. The oxygen complex which is disposed off as carbon dioxide imparts polarity to the charcoal surface, and is largely responsible for the increase in potential.