Hydrogen gas diffusion electrode in dilute sulfuric acid solution

Exptl. data of the diffusion limiting c.d. are presented for hydrogen oxidn. in a gas diffusion electrode (GDE) used in fuel cells under various conditions. The current densities were obtained using mixts. of hydrogen and inert gases. To elucidate the dependence of the overall mass transport coeff., a simplified model to describe the transport of hydrogen in a GDE, based on literature models, was derived. The GDE consists of a hydrophobic and a hydrophilic layer, i.e., a porous backing and a reaction layer. The transport rate of hydrogen under the exptl. conditions is detd. by hydrogen gas diffusion in the pores of the porous backing as well as in the macropores of the reaction layer. Diffusion of dissolved hydrogen in the micropores of the reaction layer, through the liq., is of little significanc