Back to Search
Start Over
On the molecular mechanisms for the H 2 /CO 2 separation performance of zeolite imidazolate framework two-layered membranes.
- Source :
-
Chemical science [Chem Sci] 2017 Jan 01; Vol. 8 (1), pp. 325-333. Date of Electronic Publication: 2016 Aug 09. - Publication Year :
- 2017
-
Abstract
- 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 CO <subscript>2</subscript> 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 <subscript>2</subscript> /CO <subscript>2</subscript> mixture separation of the entire membrane. This reduction would be achieved by means of a less-CO <subscript>2</subscript> -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 <subscript>2</subscript> /CO <subscript>2</subscript> separation selectivity of 9.6 together with a 250 GPU H <subscript>2</subscript> permeance at 150 °C, showing a significant improvement with respect to the pure ZIF-9 membrane. Double-layered membranes also showed higher apparent CO <subscript>2</subscript> activation energies than single-layered membranes, attributable to a diminished adsorption.
Details
- Language :
- English
- ISSN :
- 2041-6520
- Volume :
- 8
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Chemical science
- Publication Type :
- Academic Journal
- Accession number :
- 28451176
- Full Text :
- https://doi.org/10.1039/c6sc02411d