cm2008889_si_002.cif (16.54 kB)
Robust Metal–Organic Framework with An Octatopic Ligand for Gas Adsorption and Separation: Combined Characterization by Experiments and Molecular Simulation
datasetposted on 2012-01-10, 00:00 authored by Wenjuan Zhuang, Daqiang Yuan, Dahuan Liu, Chongli Zhong, Jian-Rong Li, Hong-Cai Zhou
A newly designed octatopic carboxylate ligand, tetrakis[(3,5-dicarboxyphenyl)oxamethyl]methane (TDM8–) has been used to connect a dicopper paddlewheel building unit affording a metal–organic framework (MOF), Cu4(H2O)4(TDM)·xS (PCN-26·xS, S represents noncoordinated solvent molecules, PCN = porous coordination network) with novel structure, high gas uptake, and interesting gas adsorption selectivity. PCN-26 contains two different types of cages, octahedral and cuboctahedral, to form a polyhedron-stacked three-dimensional framework with open channels in three orthogonal directions. Gas adsorption studies of N2, Ar, and H2 on an activated PCN-26 at 77 K, 1 bar, reveals a Langmuir surface area of 2545 m2/g, a Brunauer–Emmett–Teller (BET) surface area of 1854 m2/g, a total pore volume of 0.84 cm3/g, and a H2 uptake capacity of 2.57 wt %. Additionally, PCN-26 exhibits a CO2/N2 selectivity of 49:1 and CO2/CH4 selectivity of 8.4:1 at 273 K. To investigate properties of gas adsorption and the adsorption sites for CO2 in activated PCN-26, theoretical simulations of the adsorption isotherms of CO2, CH4, and N2 at different temperatures were carried out. Experimental results corroborate very well with those of molecular simulations.
surface areaadsorption sitesLangmuir surface areaMolecular SimulationAN 2Experimental resultsPCNBETOctatopic Ligandadsorption isothermsH 2CO 2MOF273 Kgas adsorption selectivityH 2 uptake capacityGas Adsorptionnovel structureCH77 KTDMgas adsorption studiesgas uptake1 baroctatopic carboxylate ligandcoordination networkorthogonal directionsdicopper paddlewheel building unitpore volumegas adsorption