  Until now, the fabrication of electrocatalysts to guarantee long life of fuel
cells and low consumption of noble metals remains a major challenge. The
electrocatalysts based on metals or metal oxides which are used today are
limited by the complexity of their synthesis processes and require several
steps before depositing the catalysts on the substrate. Herein is described a
chemical synthesis process that consists of a single-step synthesis and direct
deposition of catalysts nanoparticles such as gold (Au), palladium (Pd) and
platinum (Pt) in the thickness of a carbon-fibers-based porous transport layer
(PTL). The synthesis process essentially consists of dissolving in the same
PGMEA (Propylene glycol methyl ether acetate) solvent a metal precursor (HAuCl4
or PdNO2 or PtCl4) and a homopolymer PMMA (Polymethylmetacrylate), then the
metal solution is deposited on the surface of the PTL after cleaning. Special
emphasis is made on Pt-based materials. The obtained PTL-supported
nanoparticles were firstly characterized by scanning electron microscopy (SEM)
to evaluate their morphology, and then X-Ray diffraction (XRD) to observe the
crystal phases. To validate the methodology, Pt-coated PTL materials have been
used as anode for the borohydride oxidation reaction (BOR) in a direct
borohydride fuel cell (DBFC) and compared to a state-of-the-art nickel
electrode. There is an optimum loading of platinum (below 0.16 mg Pt/cm2) which
constitutes the best compromise between power density and faradic efficiency
for the borohydride oxidation reaction (BOR). Thanks to this low Pt loading,
hydrogen evolved during the anodic reaction is completely valorized. These
electrodes combine the advantages of high-performance with a very low metal
loading, hence lowering materials cost.
