Preparation of a Platinum and Palladium/Polyimide Nanocomposite Film as a Precursor of Metal-Doped Carbon Molecular Sieve Membrane via Supercritical Impregnation

The synthesis of a Pt- and Pd-nanoparticle-dispersed polyimide film as a precursor for the preparation of a metal-doped carbon molecular sieve (CMS) membrane for hydrogen separation has been performed. Impregnation of Pt(II) acetylacetonate and Pd(II) acetylacetonate dissolved in supercritical CO 2 yielded Pt and Pd nanoparticles (diameters 12 and 5 nm, respectively) that were highly dispersed inside polyimide films under optimized conditions. The impregnation temperature and varieties of polyimide films strongly influenced the dispersion of the metal particles. The Pd-doped CMS membrane was successfully prepared from the polyimide and Pd(II) acetylacetonate composite. It showed good hydrogen separation performance.