Thin Film Catalysts for Proton Exchange Membrane Fuel Cells

Proton-exchange membrane fuel cells use a water-based, acidic polymer membrane as an electrolyte and platinum-based electrodes. Hydrogen fuel is processed on the surface of an anode catalyst where electrons are separated from protons. The protons pass through the membrane before reaching the cathode side of the cell. Platinum-doped cerium oxide (Pt-CeO x ) thin-film catalysts are proposed to maximize the efficiency of platinum used in fuel cell anodes. The nanostructured catalysts consisting of Pt atoms, predominantly in an ionic state, dispersed within a matrix of a reducible oxide—ceria ensure that the majority of Pt atoms ends up on surfaces of the crystallites and is catalytically active. It is shown that ceria nanoparticles deposited by magnetron sputtering on a carbon substrate anchor surface Pt 2 + ions which are extremely stable and form together with ceria complex anode catalysts revealing high performance with very low Pt loading.