(US4567086-A)      Electrode substrate for fuel cells comprises a porous carbonaceous layer, a dense carbonaceouslayer having a bulk density larger than the porous layer, a separator, a dense carbonaceous layer having abulk density larger than the porous layer, and a porous carbonaceous layer, and which further comprises a number of elongated holes for feeding reactant gases into a fuel cell in the interface between the porous layer and the dense layer.c    (US4686072-A)      Prodn. of electrode substrates comprises placing (a) material for a porous carbonaceous layer; (b) material for forming elongated holes; (c) material for a dense carbonaceous layer, having a bulk density greater than that of the porous carbonaceous layer (a); (d) separator; (e) material for a second, dense carbonaceous layer; (f) material for forming a second set of elongated holes, at right angles to the former set; and (g) material for a second porous carbonaceous layer, having a bulk density less than that of the adjacent dense layer, in that order in a previously designed moulding; followed by press-moulding; post-curing; and calcination in an inert atmosphere.    USE -   The prods. are components for fuel cells. (11pp)u    (DE3512326-C)      Electrode material for fuel cells comprises two porous carbonaceous layers, two dense carbonaceous layers and a sepg. layer; with a number of canal layers arranged mutually at right angles, along which reactant fuels can be led into the body of the electrodes. The canal dia. is about 0.5-3.0 mm; the mean density of the porous carbonaceous material is 0.4-0.8 g/cm3, with porosity 50-80% (at least 60% of the pores having dia. 5-50 micro.m) and gas permeability at least 20 cm3/cm/h/mm H2O. The sepg. layer is a carbon or graphite plate. The compact carbon layers have density 0.5-1.0 g/cm3 which is greater than the adjacent porous carbon layers. The canals are arranged to bring gaseous fuels to the interfaces between the compact carbon and porous carbon layers.    USE -   The prods. ensure efficient transport of fuel to the active electrodes. (14pp)