Electrodeposition of nanostructured Pt films from lyotropic liquid crystalline phases on α-Al2O3 supported dense Pd membranes

Using the lyotropic liquid crystalline templating strategy, the nanostructured platinum film was electrochemically deposited on the α-Al₂O₃ supported dense palladium membrane. The XRD and TEM results of the Pt film revealed a hexagonal array of cylindrical pores with a uniform pore diameter of ca. 3.8 nm and a pore-to-pore separation of ca. 7.6 nm. The structure parameters of the Pt film were almost the same as those of the hexagonal liquid crystalline template. Based on SEM observations, the Pt film was featureless, smooth, and tightly adherent to the dense Pd membrane. The specific surface area of the Pt film, measured by using cyclic voltammetry, was ca. 13.8 m² g⁻¹, which was in accord with the theoretical value of 14.5 m² g⁻¹ for a perfect hexagonal nanostructure with the same structure parameters. By combining the dense Pd membrane for selective permeation to hydrogen with the Pt film of high specific surface area for catalysis, the as-synthesized two-layer film will be a promising catalytic membrane to intensify hydrogen-related reaction processes.