TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The carrier particles comprise species selected from nanometer-thickness graphite platelets, carbon nano-fibers, graphitic nano-fibers, carbon nanotubes and/or carbon nano-scrolls. The elongate-shape solid carrier particles have an aspect ratio greater than 100. The catalyst comprises a transition metal element. The solid carrier particles further comprise non-elongated graphite particles and/or carbon black particles. The carrier particles are further grafted with a proton- and/or electron-conducting polymer and the grafted particles are dispersed in the matrix material. The porous catalyst backing layer comprises a carbon paper or carbon cloth. Preferred Assembly: The assembly (A1) further comprises a porous catalyst-backing layer with a primary surface coated with an ion-conductive and electron-conductive material which is in electronic contact with the composite composition (C1).    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The composition further comprises pores that are interconnected; electronically conducting polymer which forms a polymer blend with the proton-conducting polymer; and unsupported discrete catalyst particles dispersed in the polymer. Preferred Components: The matrix material comprises a proton-conducting polymer selected from poly(perfluoro sulfonic acid), sulfonated polytetrafluoroethylene, sulfonated perfluoroalkoxy derivatives of polytetra-fluoroethylene, sulfonated polysulfone, sulfonated poly(ether ketone), sulfonated poly (ether ether ketone), sulfonated polystyrene, sulfonated polyimide, sulfonated styrene-butadiene copolymers, sulfonated poly chloro-trifluoroethylene, sulfonated perfluoroethylene-propylene copolymer, sulfonated ethylene-chlorotrifluoroethylene copolymer, sulfonated polyvinylidenefluoride, sulfonated copolymers of polyvinylidenefluoride with hexafluoropropene and tetrafluoroethylene, sulfonated copolymers of ethylene and tetrafluoroethylene, polybenzimidazole, and chemical derivatives, copolymers, and/or their blends. The matrix material comprises an electron-conducting polymer or proton-conducting polymer, which is also electronically conducting and mixture of an ion-conducting polymer and electron-conducting polymer. The electrically conducting polymer selected from sulfonated polyaniline, sulfonated polypyrrole, sulfonated poly thiophene, sulfonated bi-cyclic polymers and/or their derivatives. EXAMPLE - Bi-cyclic conducting polymer (P1) was prepared by according to US5648453. The polymer (P1) exhibited electronic conductivity of 5x 10-2 S/cm to 1.4 S/cm and proton conductivity of 5x 10-4 S/cm to 1.5x 10-2 S/cm. A polymer blend comprising bi-cyclic polymer (P1) and proton-conductive polymers selected from poly(perfluoro sulfonic acid) ( approximately 50 wt.%), sulfonated poly(ether ether ketone), sulfonated polystyrene, sulfonated poly(phthalazinon ether sulfone ketone), sulfonated polyimide and sulfonated polyaniline was prepared. The conductivity of obtained polymer blend was found to be a good matrix material for embedding the catalyst particles in a fuel cell electrode.