Ultra-low-loading pulsed-laser-deposited platinum catalyst films for polymer electrolyte membrane fuel cells

In this work experimental results are presented and analyzed for catalytic platinum films of ultra-low thickness of 0.09-3.47 nm and Pt loading of 0.18-7.44 μg cm−2 deposited using the PLD method with an ArF excimer laser (λ = 193 nm) at room temperature. For Pt deposited on the surface of the Nafion® membrane (electrolyte), in a fuel cell with PLD Pt working as oxygen cathode the peak power density is obtained equal to 59.36 mW cm−2 for the Pt loading of 1.24 μg cm−2. In the case of Pt deposition on the gas-diffusion layer (as cathode), a much higher maximum power density of 106.36 mW cm−2 at the same loading and a maximum of 188.44 mW cm−2 at the 7.44 μg cm−2 loading is observed. Experiments are also presented of Nafion® modification before the deposition of Pt on the Nafion®, in which the surface of the membranes is enlarged by bombarding with Ar ions from a plasma generator of RF 13.56 MHz. The electrochemical activity of the elements prepared by PLD is assessed in a H2/Pt/Nafion®/Pt/O2 PEMFC. The structure and morphology of the surface layers is examined by AFM and SEM microscopy.