Challenging fabrication of hollow ceramic fiber supported Cu3(BTC)2 membrane for hydrogen separation

High-performance and continuous Cu-3(BTC)(2) membranes have been successfully fabricated using a secondary growth approach on pre-seeded alpha-Al2O3 hollow ceramic fibers (HCFs) modified with chitosan. Facile synthesis of Cu-3(BTC)(2) nanocrystals can be achieved by a modified solvothermal protocol. A stable and homogeneous Cu-3(BTC)(2) seed precusor obtained with particle size of 300 nm, the size of which is suitable for seeding HCFs without any pore jam of HCFs supports (pore size of 200 nm for HCFs). A new substrate HCFs was introduced as the support of Cu-3(BTC)(2) membranes. Moreover, for the first time, chitosan is used to improve the binding force between seeds and the support owing to its abundance of both amino and hydroxyl groups. As-prepared Cu-3(BTC)(2) membrane is studied for hydrogen separation by binary gas permeation of H-2/N-2, H-2/CO2 and H-2/CH4. The synthesized membrane shows high H-2 selectivity with separation factors of 8.66, 13.56 and 6.19 for the gas mixtures of H-2/N-2, H-2/CO2 and H-2/CH4 respectively. A preferred permeance for H-2 in the binary gas mixture is obtained in the range of 3.23 x 10(-8) to 4.1 x 10(-8) mol m(-2) s(-1) Pa-1 due to the unique properties of the Cu-3(BTC)(2) MOF material, which is expected in the potential applications of industrial hydrogen recycling.