Center for Molecular Modeling - FWO J. Wieme FWO3F02015006001

High-rate nanofluidic energy absorption in porous zeolitic frameworks

sven — Thu, 22 Apr 2021 19:37:50 +0000

Y. Sun, S.M.J. Rogge, A. Lamaire, S. Vandenbrande, J. Wieme, C.R. Siviour, V. Van Speybroeck, J.-C. Tan

Nature Materials

20 (7), 1015–1023

2021

Abstract

Optimal mechanical impact absorbers are reusable and exhibit high specific energy absorption. The forced intrusion of liquid water in hydrophobic nanoporous materials, such as zeolitic imidazolate frameworks (ZIFs), presents an attractive pathway to engineer such systems. However, to harness their full potential, it is crucial to understand the underlying water intrusion and extrusion mechanisms under realistic, high-rate deformation conditions. Here, we report a critical increase of the energy absorption capacity of confined water-ZIF systems at elevated strain rates. Starting from ZIF-8 as proof-of-concept, we demonstrate that this attractive rate dependence is generally applicable to cage-type ZIFs but disappears for channel-containing zeolites. Molecular simulations reveal that this phenomenon originates from the intrinsic nanosecond timescale needed for critical-sized water clusters to nucleate inside the nanocages, expediting water transport through the framework. Harnessing this fundamental understanding, design rules are formulated to construct effective, tailorable and reusable impact energy absorbers for challenging new applications.

DOI

http://dx.doi.org/10.1038/s41563-021-00977-6

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Chlorination of a Zeolitic-Imidazolate Framework Tunes Packing and van der Waals Interaction of Carbon Dioxide for Optimized Adsorptive Separation

sven — Sun, 07 Feb 2021 12:54:58 +0000

L.H. Wee, S. Vandenbrande, S.M.J. Rogge, J. Wieme, K. Asselman, E. Jardim, J. Silvestre-Albero, J. Navarro, V. Van Speybroeck, J.A. Martens, C. Kirschhock

JACS (Journal of the American Chemical Society)

143 (13), 4962-4968

2021

Abstract

Molecular separation of carbon dioxide (CO₂) and methane (CH₄) is of growing interest for biogas upgrading, carbon capture and utilization, methane synthesis and for purification of natural gas. Here, we report a new zeolitic-imidazolate framework (ZIF), coined COK-17, with exceptionally high affinity for the adsorption of CO₂ by London dispersion forces, mediated by chlorine substituents of the imidazolate linkers. COK-17 is a new type of flexible zeolitic-imidazolate framework Zn(4,5-dichloroimidazolate)₂ with the SOD framework topology. Below 200 K it displays a metastable closed-pore phase next to its stable open-pore phase. At temperatures above 200 K, COK-17 always adopts its open-pore structure, providing unique adsorption sites for selective CO₂ adsorption and packing through van der Waals interactions with the chlorine groups, lining the walls of the micropores. Localization of the adsorbed CO₂ molecules by Rietveld refinement of X-ray diffraction data and periodic density functional theory calculations revealed the presence and nature of different adsorption sites. In agreement with experimental data, grand canonical Monte Carlo simulations of adsorption isotherms of CO₂ and CH₄ in COK-17 confirmed the role of the chlorine functions of the linkers and demonstrated the superiority of COK-17 compared to other adsorbents such as ZIF-8 and ZIF-71.

Gold Open Access

DOI

http://dx.doi.org/10.1021/jacs.0c08942

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jacs.0c08942.pdf

Pillared-layered metal-organic frameworks for mechanical energy storage applications

jelle — Thu, 01 Aug 2019 08:13:25 +0000

J. Wieme, S.M.J. Rogge, P.G. Yot, L. Vanduyfhuys, S.-K. Lee, J.-S. Chang, M. Waroquier, G. Maurin, V. Van Speybroeck

Journal of Materials Chemistry A

7 (39), 22663-22674

2019

Abstract

Herein we explore the unique potential of pillared-layered metal–organic frameworks of the DMOF-1 family for mechanical energy storage applications. In this work, we theoretically predict for the guest-free DMOF-1 a new contracted phase by exerting an external mechanical pressure of more than 200 MPa with respect to the stable phase at atmospheric pressure. The breathing transition is accompanied by a very large volume contraction of about 40%. The high transition pressures and associated volume changes make these materials highly promising with an outstanding mechanical energy work. Furthermore, we show that changing the nature of the metal allows to tune the behavior under mechanical pressure. The various phases were revealed by a combination of periodic density-functional theory calculations, force field molecular dynamics simulations and mercury intrusion experiments for DMOF-1(Zn) and DMOF-1(Cu). The combined experimental and theoretical approach allowed to discover the potential of these materials for new technological developments.

Gold Open Access

DOI

http://dx.doi.org/10.1039/C9TA01586H

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Structure–Mechanical Stability Relations of Metal-Organic Frameworks via Machine Learning

sven — Wed, 13 Feb 2019 14:35:47 +0000

P.Z. Moghadam, S.M.J. Rogge, A. Li, C.-M. Chow, J. Wieme, N. Moharrami, M. Aragones-Anglada, G. Conduit, D.A. Gomez-Gualdron, V. Van Speybroeck, D. Fairen-Jimenez

Matter

1 (1), 219-234

2019

Abstract

Assessing the mechanical stability of metal-organic frameworks (MOFs) is critical to bring these materials to any application. Here, we derive the first interactive map of the structure-mechanical landscape of MOFs by performing a multi-level computational analysis. First, we used high-throughput molecular simulations for 3,385 MOFs containing 41 distinct network topologies. Second, we developed a freely available machine-learning algorithm to automatically predict the mechanical properties of MOFs. For distinct regions of the high-throughput space, in-depth analysis based on in operando molecular dynamics simulations reveals the loss-of-crystallinity pressure within a given topology. The overarching mechanical screening approach presented here reveals the sensitivity on structural parameters such as topology, coordination characteristics and the nature of the building blocks, and paves the way for computational as well as experimental researchers to assess and design MOFs with enhanced mechanical stability to accelerate the translation of MOFs to industrial applications.

Gold Open Access

DOI

http://dx.doi.org/10.1016/j.matt.2019.03.002

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On the importance of anharmonicities and nuclear quantum effects in modelling the structural properties and thermal expansion of MOF-5

jelle — Fri, 21 Dec 2018 13:28:30 +0000

A. Lamaire, J. Wieme, S.M.J. Rogge, M. Waroquier, V. Van Speybroeck

Journal of Chemical Physics

150 (9), 094503

2019

Abstract

In this article, we investigate the influence of anharmonicities and nuclear quantum effects (NQEs) in modelling the structural properties and thermal expansion of the empty MOF-5 metal-organic framework. To introduce NQEs in classical molecular dynamics simulations, two different methodologies are considered, comparing the approximate, but computationally cheap, method of generalised Langevin equation thermostatting to the more advanced, computationally demanding path integral molecular dynamics technique. For both methodologies, similar results were obtained for all the properties under investigation. The structural properties of MOF-5, probed by means of radial distribution functions (RDFs), show some distinct differences with respect to a classical description. Besides a broadening of the RDF peaks under the influence of quantum fluctuations, a different temperature dependence is also observed due to a dominant zero-point energy (ZPE) contribution. For the thermal expansion of MOF-5, by contrast, NQEs appear to be only of secondary importance with respect to an adequate modelling of the anharmonicities of the potential energy surface (PES), as demonstrated by the use of two differently parametrised force fields. Despite the small effect in the temperature dependence of the volume of MOF-5, NQEs do however significantly affect the absolute volume of MOF-5, in which the ZPE resulting from the intertwining of NQEs and anharmonicities plays a crucial role. A sufficiently accurate description of the PES is therefore prerequisite when modelling NQEs.

DOI

http://dx.doi.org/10.1063/1.5085649

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The impact of lattice vibrations on the macroscopic breathing behavior of MIL-53(Al)

jelle — Fri, 21 Dec 2018 13:23:48 +0000

A.E.J. Hoffman, J. Wieme, S.M.J. Rogge, L. Vanduyfhuys, V. Van Speybroeck

Zeitschrift für Kristallographie - Crystalline Materials

234 (7-8), 529-545

2019

Abstract

The mechanism inducing the breathing in flexible metal-organic frameworks, such as MIL-53(Al), is still not fully understood. Herein, the influence of lattice vibrations on the breathing transition in MIL-53(Al) is investigated to gain insight in this phenomenon. Through solid-state density-functional theory calculations, the volume-dependent IR spectrum is computed together with the volume-frequency relations of all vibrational modes. Furthermore, important thermodynamic properties such as the Helmholtz free energy, the specific heat capacity, the bulk modulus, and the volumetric thermal expansion coefficient are derived via these volume-frequency relations using the quasi-harmonic approximation. The simulations expose a general volume-dependency of the vibrations with wavenumbers above 300 cm−1 due to their localized nature. In contrast, a diverse set of volume-frequency relations are observed for vibrations in the terahertz region (< 300 cm⁻¹) containing the vibrations exhibiting collective behavior. Some terahertz vibrations display large frequency differences over the computed volume range, induced by either repulsion or strain effects, potentially triggering the phase transformation. Finally, the impact of the lattice vibrations on the thermodynamic properties is investigated. This reveals that the closed pore to large pore phase transformation in MIL-53(Al) is mainly facilitated by terahertz vibrations inducing rotations of the organic linker, while the large pore to closed pore phase transformation relies on two framework-specific soft modes.

Gold Open Access

DOI

http://dx.doi.org/10.1515/zkri-2018-2154

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i-PI 2.0: A Universal Force Engine for Advanced Molecular Simulations

jelle — Sun, 24 Jun 2018 18:17:00 +0000

V. Kapil, M. Rossi, O. Marsalek, R. Petraglia, Y. Litman, T. Spura, B. Cheng, A. Cuzzocrea, R.H. Meißner, D. Wilkins, P. Juda, S.P. Bienvenue, J. Kessler, I. Poltavsky, S. Vandenbrande, J. Wieme, C. Corminboeuf, T. Kühne, D. Manolopoulos, T. Markland, J. Richardson, A. Tkatchenko, G.A. Tribello, V. Van Speybroeck, M. Ceriotti

Computer Physics Communications

236, 214-223

2019

Abstract

Progress in the atomic-scale modelling of matter over the past decade has been tremendous. This progress has been brought about by improvements in methods for evaluating interatomic forces that work by either solving the electronic structure problem explicitly, or by computing accurate approximations of the solution and by the development of techniques that use the Born-Oppenheimer (BO) forces to move the atoms on the BO potential energy surface. As a consequence of these developments it is now possible to identify stable or metastable states, to sample configurations consistent with the appropriate thermodynamic ensemble, and to estimate the kinetics of reactions and phase transitions. All too often, however, progress is slowed down by the bottleneck associated with implementing new optimization algorithms and/or sampling techniques into the many existing electronic-structure and empirical-potential codes. To address this problem, we are thus releasing a new version of the i-PI software. This piece of software is an easily extensible framework for implementing advanced atomistic simulation techniques using interatomic potentials and forces calculated by an external driver code. While the original version of the code was developed with a focus on path integral molecular dynamics techniques, this second release of i-PI not only includes several new advanced path integral methods, but also offers other classes of algorithms. In other words, i-PI is moving towards becoming a universal force engine that is both modular and tightly coupled to the driver codes that evaluate the potential energy surface and its derivatives.

http://arxiv.org/abs/1808.03824

Open Access version available at UGent repository

Green Open Access

DOI

http://dx.doi.org/10.1016/j.cpc.2018.09.020

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Tuning the balance between dispersion and entropy to design temperature-responsive flexible metal-organic frameworks

kurt — Fri, 23 Feb 2018 19:44:00 +0000

J. Wieme, K. Lejaeghere, G. Kresse, V. Van Speybroeck

Nature Communications

9, 4899

2018

DOI

http://dx.doi.org/10.1038/s41467-018-07298-4

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Wieme_2018_NatureCommun_dispersion-vs-entropy-MIL53.pdf

Efficient Construction of Free Energy Profiles of Breathing Metal-Organic Frameworks Using Advanced Molecular Dynamics Simulations

ruben — Wed, 08 Nov 2017 12:41:36 +0000

R. Demuynck, S.M.J. Rogge, L. Vanduyfhuys, J. Wieme, M. Waroquier, V. Van Speybroeck

Journal of Chemical Theory and Computation (JCTC)

13 (12), 5861-5873

2017

Abstract

In order to reliably predict and understand the breathing behavior of highly flexible metal–organic frameworks from thermodynamic considerations, an accurate estimation of the free energy difference between their different metastable states is a prerequisite. Herein, a variety of free energy estimation methods are thoroughly tested for their ability to construct the free energy profile as a function of the unit cell volume of MIL-53(Al). The methods comprise free energy perturbation, thermodynamic integration, umbrella sampling, metadynamics, and variationally enhanced sampling. A series of molecular dynamics simulations have been performed in the frame of each of the five methods to describe structural transformations in flexible materials with the volume as the collective variable, which offers a unique opportunity to assess their computational efficiency. Subsequently, the most efficient method, umbrella sampling, is used to construct an accurate free energy profile at different temperatures for MIL-53(Al) from first principles at the PBE+D3(BJ) level of theory. This study yields insight into the importance of the different aspects such as entropy contributions and anharmonic contributions on the resulting free energy profile. As such, this thorough study provides unparalleled insight in the thermodynamics of the large structural deformations of flexible materials.

Open Access version available at UGent repository

Gold Open Access

DOI

http://dx.doi.org/10.1021/acs.jctc.7b01014

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A series of sulfonic acid functionalized mixed-linker DUT-4 analogues: synthesis, gas sorption properties and catalytic performance

kevin — Fri, 28 Jul 2017 15:08:18 +0000

G. Wang, K. Leus, K. Hendrickx, J. Wieme, H. Depauw, Y-Y Liu, V. Van Speybroeck, P. Van der Voort

Dalton Transactions

46, 14356

2017

Abstract

In this work, we present the successful synthesis of a series of sulfonic acid functionalized mixed-linker metal–organic frameworks (MOFs) having the DUT-4 topology by using different ratios of 2,6-naphthalenedicarboxylic acid (H2-NDC) and 4,8-disulfonaphthalene-2,6-dicarboxylic acid (H2-NDC-2SO3H) in one-pot reactions. The obtained materials were fully characterized and their CO2 adsorption properties at low and high pressures were studied and compared with those of the pristine DUT-4 material. Generally, the CO2 adsorption capacities range from 3.28 and 1.36 mmol g−1 for DUT-4 to 1.54 and 0.78 mmol g−1 for DUT-4-SO3H (50) up to 1 bar at 273 K and 303 K, respectively. Computational calculations corroborated the structural changes of the material in function of the loading of sulfonic acid groups. Furthermore, due to the strong Brønsted acid character, the resulting sulfonic acid based MOF material was evaluated as a catalyst for the ring opening of styrene oxide with methanol as a nucleophile under mild conditions, showing almost full conversion (99%) after 5 hours of reaction. A hot filtration experiment demonstrated that the catalysis occurred heterogeneously and the catalyst could be recovered and reused for multiple runs without significant loss in activity and crystallinity.

DOI

http://dx.doi.org/10.1039/C7DT02752D

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