Ultraselective carbon molecular sieve membrane for hydrogen purification

Hydrogen is a green clean fuel and chemical feedstock. Its separation and purification from hydrogen containing mixtures is the key step in the production of hydrogen with high purity ( > 99.99%). In this work, carbon molecular sieve (CMS) membranes with ultrahigh permselectivity for hydrogen purification were fabricated by high-temperature (70 0-90 0 degrees C) pyrolysis of polymeric precursor of phenolphthalein based cardo poly(arylene ether ketone) (PEK-C). The evolution of the microstructural texture and ultramicroporous structure and gas separation performance of the CMS membrane were characterized via TG-MS, FT-IR, XRD, TEM, CO2 sorption analysis and gas permeation measurements. CMS membranes prepared at 700 degrees C exhibited amorphous turbostratic carbon structures and high H 2 permeability of 5260 Barrer with H-2/CH4, H-2/N-2 and H-2/CO selectivities of 311, 142, 75, respectively. When carbonized at 900 degrees C, the CMS membrane with ultrahigh H-2/CH4 selectivity of 1859 was derived owing to the formation of the dense and ordered carbon structure. CMS membranes with ultrahigh permselectivity exhibit an attractive application prospect in hydrogen purification. (c) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.