Energy density of a methanol/hydrogen-peroxide fuel cell

At present, the use of hydrogen and oxygen gases is necessary to achieve a reasonable power density in fuel-cell systems. However, the overall energy density of a hydrogen/oxygen fuel cell system is low in comparison with many present, or alternate, power systems, and the associated costs are high. Total energy density can be improved with the integration of a fuel reformation process, but at the cost of power density. In this paper, an alternative hydrogen peroxide/direct methanol fuel-cell system that holds potential for an increase in energy density is examined. The limiting factor in the oxidation of methanol, either through an integrated reformation process to produce hydrogen gas, or directly through increased catalyst loading, is power density. The limiting factor in hydrogen peroxide reduction is also power density, due to the complexity of the reduction process, where the preferred reduction product is water, and not the simultaneous decomposition products of oxygen and water. However, in both methanol oxidation and hydrogen peroxide reduction, energy density is not sacrificed to a large extent, and the resulting system has utility in the future as a viable power plant due to advances in both catalysis of direct methanol oxidation, and direct hydrogen peroxide reduction. (C) 2002 Elsevier Science Ltd. All rights reserved.