Computational Investigations of Metal–Organic Frameworks as Sorbents for BTEX Removal

Abstract

Sequestration of aromatic volatile organic compounds (VOCs) via metal− organic frameworks (MOFs) as sorbents is a viable means of environmental preservation. In this investigation, we shed light on the key features associated with MOFs that govern the selective uptake of a subclass of VOCs containing benzene, toluene, ethylbenzene, and xylenes (BTEX). We investigate, through a multistep computational framework including ab initio electronic structure and classical molecular dynamics simulations, the energetic and dynamical properties associated with BTEX capture in three MOFs: HKUST-1, ZIF-8, and MIL-53. Our work demonstrates the importance of considering both static and dynamical properties upon introduction of guest molecules in such computational investigations. We elucidate the key geometric factors associated with efficient capture of BTEX compounds and highlight possible postsynthetic modifications that can be used to produce next generation sorbents for BTEX capture.

Butterfly, Vinylidene‐Like, Monobridged and Trans Structures of Si2H2+: Comparison to the Well‐Characterized Neutral Si2H2

“…Equilibrium geometries and harmonic vibrational frequencies of each isomer were predicted using coupled cluster theory with singles, doubles, and perturbative triple excitations [CCSD(T)] [37] and the cc‐pVQZ Dunning basis set [38–40] . Each isomer was optimized with a positive charge, using neutral Si 2 H 2 data that has been reported in the past to start.…”

Investigating the Increased CO2 Capture Performance of Amino Acid Functionalized Nanoporous Materials from First-Principles and Grand Canonical Monte Carlo Simulations

“…Metal–organic frameworks (MOFs) and covalent-organic frameworks (COFs) are classes of materials now ubiquitously utilized in environmental-science-based applications. − MOFs comprise metal-oxide nodes linked by organic ligands to generate a crystalline framework, one of whose defining characteristic is an extremely high surface area to volume ratio . The closely related COFs are also crystalline materials where the metal-oxide node is either entirely absent, allowing long organic molecules to generate the resulting crystal structure, or is replaced by a large macrocycle such as a porphyrin, anchoring the linkers and providing additional structural stability. − Their large surface area to volume ratio combined with their high adsorption capacities, regeneration potential, and adaptable chemical composition make MOFs and COFs uniquely versatile and effective platforms for small molecule sequestration and contaminant capture. − With this being the case, nanoporous frameworks like MOFs and COFs were quickly identified as key candidates to address one of the leading global issues, the large-scale and sustained emission of greenhouse gases like CO 2 . − Given the long history of CO 2 capture efforts as a means of environmental remediation, MOFs and COFs have seen extensive application in this field with varied success. − …”

Molecular Dynamics Simulation of the Adsorption and Diffusion of C8 Aromatic Isomers in MIL-47(V)

“…In particular, specific adsorption sites of MOF surfaces that include aromatic hydrocarbon compounds, organic ligands, and functional groups can enhance the removal efficiency of adsorbents by hydrogen bonds, π−π interactions, and electrostatic interactions. 29 MOFs with designable pore apertures and selective binding sites put forward unlimited potential for the specific identification of C 8 aromatic isomers. 30 According to the current research progress, a variety of MOF materials have been used for the effective adsorption and separation of C 8 aromatic isomers, for example, ZU-61, 20 ZUL-C3, 31 NU-2000, and NU-2001.…”

“…Compared with traditional adsorbents, MOFs have unparalleled superiority and prospects in adsorption and separation because of aperture tunability, diverse structure and shapes, and chemical functionalities. − Recently, it has previously been reported for the adsorption and separation of hydrocarbon mixtures (ethane/ethylene, propane/propylene, and C 6 alkane mixtures). − In fact, one of the most potential developments of MOFs is that C 8 aromatic isomers can be separated through the interaction of pore size and its skeleton with C 8 aromatic isomers. In particular, specific adsorption sites of MOF surfaces that include aromatic hydrocarbon compounds, organic ligands, and functional groups can enhance the removal efficiency of adsorbents by hydrogen bonds, π–π interactions, and electrostatic interactions . MOFs with designable pore apertures and selective binding sites put forward unlimited potential for the specific identification of C 8 aromatic isomers …”