Plasma deposited Pt-containing hydrocarbon thin films as electrocatalysts for PEM fuel cell

High performance electrocatalytic hydrocarbon thin films containing Pt nano-clusters are deposited by simultaneous plasma polymerization of ethylene and sputtering of a Pt target. The proposed synthetic approach largely simplifies the PEMFC electrocatalyst fabrication process with respect to conventional methods. The deposition of the hydrocarbon matrix provides the mechanical support and electronic continuity, ensuring a uniform metal dispersion, avoiding Pt nanoparticle agglomeration. The Pt catalyst is dispersed as small vertically stacked clusters with size less than 10 nm in columnar thin (250-500 nm) films. PEMFC testing with plasma deposited 500 nm thick film and 0.513 mg cm2 Pt load as anodic electrocatalyst led to a maximum reproducible power density as high as 300 mW cm2.