Recent Advances in Molecular Dynamics Simulations of Gas Diffusion in Metal Organic Frameworks

Keskın, Seda

doi:10.5772/35925

Cited by 8 publications

(8 citation statements)

References 111 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additionally, molecular dynamics simulations have been applied to study the framework and the motion of small molecules in MOFs, including the calculation of diffusion constants. 6 , 7 Classical force fields have been developed specifically for treating guest binding in MOFs and for the bonding interactions within the frameworks. 4 , 8 These force fields as well as semiempirical methods have been used to optimize framework geometries, particularly when breathing motions in MOFs are important or when a large database of MOFs is studied and optimizations with higher levels of theory are intractable.…”

Section: Introductionmentioning

confidence: 99%

“…Gas adsorption can be modeled using Monte Carlo simulations where thermodynamic properties (most often the heat of adsorption and the loading of guest molecules at a given temperature and pressure) are calculated as an ensemble average. , This is particularly important, since gas molecules generally physisorb in the MOF and at finite temperatures can access many binding configurations. Additionally, molecular dynamics simulations have been applied to study the framework and the motion of small molecules in MOFs, including the calculation of diffusion constants. , Classical force fields have been developed specifically for treating guest binding in MOFs and for the bonding interactions within the frameworks. , These force fields as well as semiempirical methods have been used to optimize framework geometries, particularly when breathing motions in MOFs are important or when a large database of MOFs is studied and optimizations with higher levels of theory are intractable. − …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Performance of van der Waals Corrected Functionals for Guest Adsorption in the M₂(dobdc) Metal–Organic Frameworks

Vlaisavljevich¹,

Huck²,

Hulvey

et al. 2017

J. Phys. Chem. A

View full text Add to dashboard Cite

Small-molecule binding in metal–organic frameworks (MOFs) can be accurately studied both experimentally and computationally, provided the proper tools are employed. Herein, we compare and contrast properties associated with guest binding by means of density functional theory (DFT) calculations using nine different functionals for the M2(dobdc) (dobdc4– = 2,5-dioxido,1,4-benzenedicarboxylate) series, where M = Mg, Mn, Fe, Co, Ni, Cu, and Zn. Additionally, we perform Quantum Monte Carlo (QMC) calculations for one system to determine if this method can be used to assess the performance of DFT. We also make comparisons with previously published experimental results for carbon dioxide and water and present new methane neutron powder diffraction (NPD) data for further comparison. All of the functionals are able to predict the experimental variation in the binding energy from one metal to the next; however, the interpretation of the performance of the functionals depends on which value is taken as the reference. On the one hand, if we compare against experimental values, we would conclude that the optB86b-vdW and optB88-vdW functionals systematically overestimate the binding strength, while the second generation of van der Waals (vdW) nonlocal functionals (vdw-DF2 and rev-vdW-DF2) correct for this providing a good description of binding energies. On the other hand, if the QMC calculation is taken as the reference then all of the nonlocal functionals yield results that fall just outside the error of the higher-level calculation. The empirically corrected vdW functionals are in reasonable agreement with experimental heat of adsorptions but under bind when compared with QMC, while Perdew–Burke–Ernzerhof fails by more than 20 kJ/mol regardless of which reference is employed. All of the functionals, with the exception of vdW-DF2, predict reasonable framework and guest binding geometries when compared with NPD measurements. The newest of the functionals considered, rev-vdW-DF2, should be used in place of vdW-DF2, as it yields improved bond distances with similar quality binding energies.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Performance of van der Waals Corrected Functionals for Guest Adsorption in the M₂(dobdc) Metal–Organic Frameworks

Vlaisavljevich¹,

Huck²,

Hulvey

et al. 2017

J. Phys. Chem. A

View full text Add to dashboard Cite

show abstract

“…MOFs have been considered as promising adsorbents and membranes due to their wide range of pore sizes and shapes, low densities (0.2−1 g/cm 3 ), large surface areas (500−6000 m 2 /g), high porosities, and reasonable thermal and mechanical stabilities. 10 experimentally 11 and computationally 1,12,13 studied for many different gas separations. Most of these studies have focused on the CO 2 separation and examined separation of either CO 2 / CH 4 or CO 2 /N 2 mixtures using MOFs.…”

Section: Introductionmentioning

confidence: 99%

“…Thousands of MOFs have been synthesized to date, and theoretically an unlimited number of structures can be synthesized by combining different metals and organic linkers. MOFs have been considered as promising adsorbents and membranes due to their wide range of pore sizes and shapes, low densities (0.2–1 g/cm 3 ), large surface areas (500–6000 m 2 /g), high porosities, and reasonable thermal and mechanical stabilities . MOFs have been experimentally and computationally ,, studied for many different gas separations.…”

Section: Introductionmentioning

confidence: 99%

Adsorption- and Membrane-Based CH₄/N₂ Separation Performances of MOFs

Sumer

Keskın

2017

Ind. Eng. Chem. Res.

Self Cite

View full text Add to dashboard Cite

Metal organic frameworks (MOFs) have been widely studied as adsorbents and membranes for gas separation applications. Considering the large number of available MOFs, it is not possible to fabricate and test the gas separation performance of every single MOF using purely experimental methods. In this study, we used molecular simulations to assess both adsorption-based and membrane-based CH4/N2 separation performances of 102 different MOFs. This is the largest number of MOF adsorbents and membranes studied to date for separation of CH4/N2 mixtures. Several adsorbent evaluation metrics such as adsorption selectivity, working capacity, and regenerability were predicted, and the top performing adsorbents were identified. Several MOFs were predicted to exhibit higher adsorption selectivities than the traditional adsorbents such as zeolites and activated carbons. Relation between adsorption-based separation performances of MOFs and their structural properties were also investigated. Results showed that MOFs having the largest cavity diameters in the range of 4.6–5.4 Å, pore limiting diameters in the range of 2.4–3.7 Å, surface areas less than 2000 m2/g, and porosities less than 0.5 are promising adsorbents for CH4/N2 separations. We then combined adsorption and diffusion data obtained from molecular simulations and predicted both membrane selectivities and gas permeabilities of MOFs for separation of CH4/N2 mixtures. A significant number of MOF membranes were identified to be CH4 selective in contrast to the traditional membrane materials which are generally N2 selective. Several MOFs exceeded the upper bound established for the polymeric membranes, and many MOFs exhibited higher gas permeabilities than zeolites. The results of this study will be useful to guide the experiments to the most promising MOF adsorbents and membranes for efficient separation of CH4/N2 mixtures.

show abstract

“… 3 They have well-defined pore structures, 4 large surface areas (500–6500 m 2 g –1 ), 5 high porosities, good thermal and mechanical stabilities which make them strong candidates for gas separation applications. 6 , 7 MOFs have been widely studied for adsorption of CO 2 , CH 4 , and H 2 in addition to the separation of several gas mixtures including CO 2 /CH 4 , CH 4 /H 2 , CO 2 /N 2 , CO 2 /H 2 and noble gases. 8 – 12 Most of the studies related to the gas separation with MOFs in the literature focused on the CO 2 capture whereas research on C 2 H 6 separation using MOFs has recently started.…”

Section: Introductionmentioning

confidence: 99%

Molecular simulations of MOF membranes for separation of ethane/ethene and ethane/methane mixtures

Altıntaş

Keskın

2017

RSC Adv.

Self Cite

View full text Add to dashboard Cite

show abstract

Recent Advances in Molecular Dynamics Simulations of Gas Diffusion in Metal Organic Frameworks

Cited by 8 publications

References 111 publications

Performance of van der Waals Corrected Functionals for Guest Adsorption in the M₂(dobdc) Metal–Organic Frameworks

Performance of van der Waals Corrected Functionals for Guest Adsorption in the M₂(dobdc) Metal–Organic Frameworks

Adsorption- and Membrane-Based CH₄/N₂ Separation Performances of MOFs

Molecular simulations of MOF membranes for separation of ethane/ethene and ethane/methane mixtures

Contact Info

Product

Resources

About

Recent Advances in Molecular Dynamics Simulations of Gas Diffusion in Metal Organic Frameworks

Cited by 8 publications

References 111 publications

Performance of van der Waals Corrected Functionals for Guest Adsorption in the M2(dobdc) Metal–Organic Frameworks

Performance of van der Waals Corrected Functionals for Guest Adsorption in the M2(dobdc) Metal–Organic Frameworks

Adsorption- and Membrane-Based CH4/N2 Separation Performances of MOFs

Molecular simulations of MOF membranes for separation of ethane/ethene and ethane/methane mixtures

Contact Info

Product

Resources

About

Performance of van der Waals Corrected Functionals for Guest Adsorption in the M₂(dobdc) Metal–Organic Frameworks

Performance of van der Waals Corrected Functionals for Guest Adsorption in the M₂(dobdc) Metal–Organic Frameworks

Adsorption- and Membrane-Based CH₄/N₂ Separation Performances of MOFs