Preparation and application of supported palladium-modified polyimide-silica hybrid membrane for selective separation of H2

The palladium-modified polyimide-silica (Pd-PI-SiO2) hybrid membrane supported on the kieselguhrmullite ceramic membrane substrate with a. TiO2 transition layer was prepared by the sol-gel method. Infrared spectroscopy, scanning electron microscopy, low temperature N-2 adsorption, and gas permeability measurement techniques were used to characterize its structure, micro-surface, pore distribution, and permeability for CH4, H2O, H-2, CO2, CO, and N-2. The results indicate that a bond is formed between PI and SiO2, and palladium exists in the hybrid membrane as a metallic state with good distribution, which can modify the micro-pore structure of the PI-SiO2 membrane. The pore diameter of the Pd-PI-SiO2 membrane is about 4 nm. The gas permeability measurements show that the N-2 permeance flux of this hybrid membrane is 0.2 X 10(-7) Mol/(m(2.)Pa(.)s), and the separation coefficient of H-2/N-2 is 542. Palladium has an adsorption effect for hydrogen, which can promote the separation of hydrogen from the gaseous mixture.