Porous Polyethersulfone-Supported Zeolitic Imidazolate Framework Membranes for Hydrogen Separation

ZIF-8 thin layer has been synthesized on the asymmetric porous polyethersulfone (PES) substrate via secondary seeded growth. Continuous and dense ZIF-8 layer, containing microcavities, has good affinity with the PES support. Single gas permeance was measured for H-2, N-2, CH4, O-2, and Ar at different pressure gradients and temperatures. Molecular sieving separation has been achieved for selectively separating hydrogen from larger gases. At 333 K, the H-2 permeance can reach similar to 4 x 10(-7) mol m(-2) s(-1) Pa-1, and the ideal separation factors of H-2 from Ar, O-2, N-2, and CH4, are 9.7, 10.8, 9.9, and 10.7, respectively. Long-term hydrogen permeance and H-2/N-2 separation performance show the stable permeability of the derived membranes.