Synthesis of nanostructured electrocatalysts based on magnetron ion sputtering

Abstract

Nanostructured platinum catalysts for electrochemical systems with proton-exchange membranes (PEMs) have been synthesized by magnetron ion sputtering on a carbon support. The design of the powder support stirrer has been optimized to ensure uniform surface coverage with platinum metal nanoparticles. The deposition parameters (discharge power, deposition time, and bias voltage) that make it possible to obtain electrocatalysts with a large specific surface area (up to 44 m²/g) have been determined. The resulting catalysts have been studied by transmission electron microscopy and X-ray diffraction. The samples with platinum particles 3 to 4 nm in size uniformly distributed over the carbon surface and forming a single phase exhibit the greatest efficiency. The electrodes based on the synthesized electrocatalysts have been tested in a liquid electrolyte and as a component of a fuel cell and PEM water electrolyzer. The voltage across the fuel cell with the synthesized Pt/C electrocatalyst (44 m²/g) at a current density of 1 A/cm² is as high as 0.55 V, which corresponds to a specific power of 550 mW/cm². Qualitative correlations between the parameters of the synthesized catalysts and the deposition conditions have been established.