title: Screening metal-organic frameworks for selective noble gas adsorption in air: effect of pore size and framework topology.
abstract: The adsorption of noble gases and nitrogen by sixteen metal-organic frameworks (MOFs) was investigated using grand canonical Monte Carlo simulation. The MOFs were chosen to represent a variety of net topologies, pore dimensions, and metal centers. Three commercially available MOFs (HKUST-1, AlMIL-53, and ZIF-8) and PCN-14 were also included for comparison. Experimental adsorption isotherms, obtained from volumetric and gravimetric methods, were used to compare krypton, argon, and nitrogen uptake with the simulation results. Simulated trends in gas adsorption and predicted selectivities among the commercially available MOFs are in good agreement with experiment. In the low pressure regime, the expected trend of increasing adsorption with increasing noble gas polarizabilty is seen. For each noble gas, low pressure adsorption correlates with several MOF properties, including free volume, topology, and metal center. Additionally, a strong correlation exists between the Henry's constant and the isosteric heat of adsorption for all gases and MOFs considered. Finally, we note that the simulated and experimental gas selectivities demonstrated by this small set of MOFs show improved performance compared to similar values reported for zeolites.
authors: Geochemistry Department, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
authors: Marie V
authors: MV
authors: Parkes
authors: Chad L
authors: CL
authors: Staiger
authors: John J
authors: JJ
authors: Perry
authors: Mark D
authors: MD
authors: Allendorf
authors: Jeffery A
authors: JA
authors: Greathouse
mesh_terms: D000327:Adsorption; D000388:Air / Q000032:analysis; D003198:Computer Simulation; D000073396:Metal-Organic Frameworks; D008956:Models, Chemical; D008958:Models, Molecular; D009010:Monte Carlo Method; D005741:Noble Gases / Q000302:isolation & purification*; D009942:Organometallic Compounds / Q000737:chemistry*; D016062:Porosity
chemical_list: D000073396:Metal-Organic Frameworks; D005741:Noble Gases; D009942:Organometallic Compounds; C539834:bis(1,3,5-benzenetricarboxylate)tricopper(II)