Characterization of a monolithic mesoporous carbon as diffusion layer for micro fuel cells application

The preparation and characterization of amonolithicmesoporouscarbon structure, which could be used as diffusionlayer in PEM and DMPEM microfuelcells, is described. Several characteristics of the monolithiccarbon were studied, such as specific surface area, pore size distribution, bulk electrical resistivity, contact resistance with graphite plates, along with the wettability, imbibition and permeability of methanol aqueous solution. These properties were compared to those reported for commercial carbon paper and carbon cloth materials commonly used as diffusionlayers in PEM fuelcells. The electrical properties of the mesoporouscarbon meet the requirements to be employed as diffusionlayers in PEM stacks assembled at pressures above 15 bar. The rapid spreading and imbibition of concentrated methanol solutions in the mesoporouscarbon, as well as the permeability of the aqueous methanol through it, also make this mesostructured carbona possible candidate for diffusionlayer and catalyst support in passive direct methanol microfuelcells.