Página principal > Artículos > On the molecular mechanisms for the H2/CO2 separation performance of zeolite imidazolate framework two-layered membranes
Resumen: 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 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. Idioma: Inglés DOI: 10.1039/C6SC02411D Año: 2017 Publicado en: CHEMICAL SCIENCE 8 (2017), 325-333 ISSN: 2041-6520 Factor impacto JCR: 9.063 (2017) Categ. JCR: CHEMISTRY, MULTIDISCIPLINARY rank: 18 / 171 = 0.105 (2017) - Q1 - T1 Factor impacto SCIMAGO: 4.508 - Chemistry (miscellaneous) (Q1)