Simulation of H<sub>2</sub>/CH<sub>4</sub> mixture permeation through MOF membranes using non-equilibrium molecular dynamics

Velioğlu, Sadiye; Keskın, Seda

doi:10.1039/c8ta10167a

Cited by 39 publications

(69 citation statements)

References 72 publications

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“…Note that at very low adsorbate loadings, the thermodynamic factor Γ is close to unity and the corrected, transport, and self-diffusivities all coincide. Non-equilibrium MD techniques, which incorporate a gradient of concentration under steady-state or non-steady-state conditions, can also be used to obtain transport diffusion coefficients [20][21][22][23].…”

Section: Simulation Methods Overviewmentioning

confidence: 99%

Connecting theory and simulation with experiment for the study of diffusion in nanoporous solids

et al. 2021

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Nanoporous solids are ubiquitous in chemical, energy, and environmental processes, where controlled transport of molecules through the pores plays a crucial role. They are used as sorbents, chromatographic or membrane materials for separations, and as catalysts and catalyst supports. Defined as materials where confinement effects lead to substantial deviations from bulk diffusion, nanoporous materials include crystalline microporous zeotypes and metal–organic frameworks (MOFs), and a number of semi-crystalline and amorphous mesoporous solids, as well as hierarchically structured materials, containing both nanopores and wider meso- or macropores to facilitate transport over macroscopic distances. The ranges of pore sizes, shapes, and topologies spanned by these materials represent a considerable challenge for predicting molecular diffusivities, but fundamental understanding also provides an opportunity to guide the design of new nanoporous materials to increase the performance of transport limited processes. Remarkable progress in synthesis increasingly allows these designs to be put into practice. Molecular simulation techniques have been used in conjunction with experimental measurements to examine in detail the fundamental diffusion processes within nanoporous solids, to provide insight into the free energy landscape navigated by adsorbates, and to better understand nano-confinement effects. Pore network models, discrete particle models and synthesis-mimicking atomistic models allow to tackle diffusion in mesoporous and hierarchically structured porous materials, where multiscale approaches benefit from ever cheaper parallel computing and higher resolution imaging. Here, we discuss synergistic combinations of simulation and experiment to showcase theoretical progress and computational techniques that have been successful in predicting guest diffusion and providing insights. We also outline where new fundamental developments and experimental techniques are needed to enable more accurate predictions for complex systems.

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Section: Simulation Methods Overviewmentioning

confidence: 99%

Connecting theory and simulation with experiment for the study of diffusion in nanoporous solids

et al. 2021

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“…Although the thickness of experimentally tested MOF membranes is higher than the computationally simulated ones, the thickness of MOF membranes is taken as approximately 40-50 Å in computational studies to save computational time. [81][82][83] Therefore, considering mass transfer resistance in simulations is important to mimic the real gas separation unit. Different than the GCMC + EMD approach, membrane properties are directly computed from NEMD simulations.…”

Section: Materials Advances Reviewmentioning

confidence: 99%

“…So far, we discussed GCMC + EMD approach which is based on the equilibrium conditions to predict membrane properties of MOF membranes. Velioglu and Keskin 83 compared calculated H 2 and CH 4 permeabilities and selectivities of ZIF-8 obtained from GCMC + EMD and NEMD simulations with the experiments in Fig. 5(a)–(c) .…”

Section: Simulated Membrane Properties Of Mofsmentioning

confidence: 99%

Recent advances in simulating gas permeation through MOF membranes

2021

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“… 39 In 2019, Velioglu and Keskin implemented an EF-NEMD for the separation of a H 2 /CH 4 mixture with MOF nanosheets and compared their results to EMD and GCMC simulations with the former method achieving a better agreement with the experimental data. 40 …”

Section: Introductionmentioning

confidence: 99%

Understanding CO₂/CH₄ Separation in Pristine and Defective 2D MOF CuBDC Nanosheets via Nonequilibrium Molecular Dynamics

Kallo

Lennox

2020

Langmuir

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The separation of CO 2 /CH 4 gas mixtures is a key challenge for the energy sector and is essential for the efficient upgrading of natural gas and biogas. A new emerging field, that of metal−organic framework nanosheets (MONs), has shown the potential to outperform conventional separation methods and bulk metal−organic frameworks (MOFs). In this work, we model the CO 2 /CH 4 separation in both defect-free and defective 2D CuBDC nanosheets and compare their performance with the bulk CuBDC MOF and experimental data. We report the results of external force nonequilibrium molecular dynamics (EF-NEMD) for pure components and binary mixtures. The EF-NEMD simulations reveal a pore blocking separation mechanism, in which the CO 2 molecules occupy adsorption sites and significantly restrict the diffusion of CH 4 . The MON structure achieves a better selectivity of CO 2 over CH 4 compared to the bulk CuBDC MOF which is due to the mass transfer resistance of the methane molecules on the surface of the nanosheet. Our results show that it is essential to consider the real mixture in these systems rather than relying solely on pure component data and ideal selectivity. Furthermore, the separation is shown to be sensitive to the presence of missing linker defects in the nanosheets. Only 10% of missing linkers result in nonselective nanosheets. Hence, the importance of a defect-free synthetic method for CuBDC nanosheets is underlined.

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Simulation of H₂/CH₄ mixture permeation through MOF membranes using non-equilibrium molecular dynamics

Abstract: External field non-equilibrium molecular dynamics (NEMD) simulations were used to directly compute gas permeation through MOF membranes.

Cited by 39 publications

References 72 publications

Connecting theory and simulation with experiment for the study of diffusion in nanoporous solids

Connecting theory and simulation with experiment for the study of diffusion in nanoporous solids

Recent advances in simulating gas permeation through MOF membranes

Understanding CO₂/CH₄ Separation in Pristine and Defective 2D MOF CuBDC Nanosheets via Nonequilibrium Molecular Dynamics

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Simulation of H2/CH4 mixture permeation through MOF membranes using non-equilibrium molecular dynamics

Abstract: External field non-equilibrium molecular dynamics (NEMD) simulations were used to directly compute gas permeation through MOF membranes.

Cited by 39 publications

References 72 publications

Connecting theory and simulation with experiment for the study of diffusion in nanoporous solids

Connecting theory and simulation with experiment for the study of diffusion in nanoporous solids

Recent advances in simulating gas permeation through MOF membranes

Understanding CO2/CH4 Separation in Pristine and Defective 2D MOF CuBDC Nanosheets via Nonequilibrium Molecular Dynamics

Contact Info

Product

Resources

About

Simulation of H₂/CH₄ mixture permeation through MOF membranes using non-equilibrium molecular dynamics

Understanding CO₂/CH₄ Separation in Pristine and Defective 2D MOF CuBDC Nanosheets via Nonequilibrium Molecular Dynamics