doi:10.1039/C6SC02411DengCacho Bailo, FernandoMatito-Martos, IsmaelPérez-Carbajo, JulioEtxeberría-Benavides, MirenKarvan, OguzSebastián, VíctorCalero, SofíaTéllez, CarlosCoronas, JoaquínOn the molecular mechanisms for the H2/CO2 separation performance of zeolite imidazolate framework two-layered membranesART-2017-101458Double-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 H2/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 H2/CO2 separation selectivity of 9.6 together with a 250 GPU H2 permeance at 150 °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.2017http://zaguan.unizar.es/record/6284210.1039/C6SC02411Dhttp://zaguan.unizar.es/record/62842oai:zaguan.unizar.es:62842info:eu-repo/grantAgreement/ES/MINECO/MAT2013-40566-Rinfo:eu-repo/grantAgreement/EC/FP7/321642/EU/Development of a microfluidic platform to produce nanomaterials and assessment on new nanotechnology applications/PLATFORM2NANOinfo:eu-repo/grantAgreement/EC/FP7/279520/EU/Towards more efficient materials for technological processes/RASPAinfo:eu-repo/grantAgreement/ES/DGA/T05CHEMICAL SCIENCE 8 (2017), 325-333by-nchttp://creativecommons.org/licenses/by-nc/3.0/es/info:eu-repo/semantics/openAccess