%0 Journal Article %A Cacho-Bailo, Fernando %A Matito-Martos, Ismael %A Perez-Carbajo, Julio %A Etxeberría-Benavides, Miren %A Karvan, Oğuz %A Sebastián, Víctor %A Calero, Sofía %A Téllez, Carlos %A Coronas, Joaquín %T On the molecular mechanisms for the H2/CO2 separation performance of zeolite imidazolate framework two-layered membranes %D 2017 * ROYAL SOC CHEMISTRY, THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND %X Double-layered zeolitic imidazolate framework (ZIF) membranes were fabricated inside polyimide P84 hollow fibers by a step-synthesis conducted by microfluidic technology and applied to pre-combustion gas separation. Our hypothesis, based on the information provided by a combination of molecular simulation and experiments, is that a CO2 adsorption reduction on the surface of the ZIF-9 would enhance the molecular sieving effect of this ZIF-9 layer and therefore the selectivity in the H-2/CO2 mixture separation of the entire membrane. This reduction would be achieved by means of a less-CO2-adsorptive methylimidazolate-based ZIF-67 or ZIF-8 layer coating the ZIF-9. ZIF-8/ZIF-9 and ZIF-67/ZIF-9 double-layered membranes were prepared and characterized by XRD, FTIR, SEM, FIB, TEM and EDS. This unprecedented strategy led to a H-2/CO2 separation selectivity of 9.6 together with a 250 GPU H-2 permeance at 150 degrees C, showing a significant improvement with respect to the pure ZIF-9 membrane. Double-layered membranes also showed higher apparent CO2 activation energies than single-layered membranes, attributable to a diminished adsorption. %@ 2041-6520 %K CARBON-DIOXIDE ADSORPTION %K MIXED-MATRIX MEMBRANES %K CO2 SEPARATION %K HYDROGEN SELECTIVITY %K COMPOSITE MEMBRANES %K PHASE-TRANSITION %K LINKER SYNTHESIS %K ZIF-90 MEMBRANE %K GAS SEPARATION %K HOLLOW-FIBER doi 10.1039/c6sc02411d %U http://hdl.handle.net/11556/378 %~ GOEDOC, SUB GOETTINGEN