RESUMEN
Natural gas plays a crucial role in daily and industrial production, but the impurities contained in natural gas limit its further use. It is very important to develop adsorbents that can separate CH4 from multicomponent mixtures, but there are still many challenges and problems. Herein, a novel porous MOF {[Mn5(pbdia)2(CO3)(H2O)2] â 5H2O â 2DMF}n (pbdia = 2,2'-(5-carboxy-1,3-phenylene)bis(oxy) diterephthalic acid) was successfully synthesized based on a flexible pentacarboxylic acid ligand and a unique pentanuclear Mn5(COO)10CO3 cluster. The MOF reveals a 3D porous structure with 2D intersecting channels, which shows high C3H8, C2H6, and CO2 adsorption capacities and affinities over CH4. Moreover, the ideal adsorption solution theory selectivities of C3H8/CH4, C2H6/CH4, and CO2/CH4 can reach 263.0, 27.0, and 7.7, respectively, suggesting a potential for removing the low content of C3H8, C2H6, and CO2 from pipeline natural gas, which was further confirmed by breakthrough curves and GCMC simulations.
RESUMEN
The achievement of direct C2H4 separation from C2 hydrocarbons is very challenging in the petrochemical industry due to their similar molecular sizes, boiling points, and physicochemical properties. In this work, a nonpolar/inert ultramicroporous metal-organic framework (MOF), [Co3(µ3-OH)(tipa)(bpy)1.5]·3DMF·6H2O (1), with stand-alone one-dimensional square tubular channels was successfully constructed, its pore enriched with plenty of aromatic rings causing nonpolar/inert pore surfaces. The MOF shows preferential adsorption of C2H6 compared to C2H4 and C2H2 in the low-pressure region, which is further verified by adsorption heats and selectivities. The C2H4 separation potential in one step for binary C2H6/C2H4 (50/50 and 10/90) and ternary C2H4/C2H6/C2H2 (89/10/1) is also examined by transient breakthrough simulations. Moreover, grand canonical Monte Carlo simulations demonstrate that the unique reversed adsorption mechanism is due to the shortest and most number of C-H···π interactions between C2H6 and the framework.
RESUMEN
The accurate design and systematic engineering of MOFs is a large challenge due to the randomness of the synthesis process. Isoreticular chemistry provides a powerful approach for the regulation of pore environment in a more predictable and precise way to systematically control gas/vapor adsorption performances. Herein, utilizing an effective strategy of altering the "pillared" motifs of pillared layer structures, three isoreticular ultramicroporous MOFs were successfully constructed. Combined with the reported parent MOFs and two other recorded isoreticular MOFs modified with -NH2 and -CH3, gas and vapor uptake performances of this family of isoreticular pillared layer MOFs were systematically explored.
