Van der Waals density functional study of hydrocarbon adsorption and separation in metal–organic frameworks without open metal sites

Abstract Metal–organic frameworks (MOFs) have received significant attention thanks to their promising features in the storage and separation of guest molecules. MOFs without open metal sites are emerging as they are often less susceptible to poisoning compared to those with open metal sites. However, a complete understanding of the binding and gas separation mechanisms in such materials is still missing. In this work, we perform a comparative study of two classes of vanadium-based MOFs without open metal sites: MFM-300-V$$^\text{(III)}$$ (III) and MFM-300-V$$^\text{(IV)}$$ (IV) , as well as MIL-47-V$$^\text{(III)}$$ (III) and MIL-47-V$$^\text{(IV)}$$ (IV) . We employ first-principles van der Waals density functional theory to find the optimal binding conformations and binding energies of a series of small hydrocarbons within the pores of the aforementioned MOFs. Our study provides insight into the host–guest interactions in such MOFs without open metal sites, especially the role played by the bridging hydroxyl group ($$\mu _2$$ μ 2 –OH). We conclude that the bridging –OH group acts as a pseudo open metal site in these MOFs. Graphic abstract

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Tuning the Redox Activity of Metal−Organic Frameworks for Enhanced, Selective O2 Binding

10.26434/chemrxiv.10316681.v1 ◽

2019 ◽

Author(s):

Andrew Rosen ◽

M. Rasel Mian ◽

Timur Islamoglu ◽

Haoyuan Chen ◽

Omar Farha ◽

...

Keyword(s):

Density Functional ◽

Metal Organic Frameworks ◽

Redox Activity ◽

Screening Methods ◽

Bridging Ligands ◽

Metal Centers ◽

Computational Screening ◽

Open Metal Sites ◽

Metal Organic ◽

Unsaturated Metal Sites

Metal−organic frameworks (MOFs) with coordinatively unsaturated metal sites are appealing as adsorbent materials due to their tunable functionality and ability to selectively bind small molecules. Through the use of computational screening methods based on periodic density functional theory, we investigate O2 and N2 adsorption at the coordinatively unsaturated metal sites of several MOF families. A variety of design handles are identified that can be used to modify the redox activity of the metal centers, including changing the functionalization of the linkers (replacing oxido donors with sulfido donors), anion exchange of bridging ligands (considering μ-Br-, μ-Cl-, μ-F-, μ-SH-, or μ-OH- groups), and altering the formal oxidation state of the metal. As a result, we show that it is possible to tune the O2 affinity at the open metal sites of MOFs for applications involving the strong and/or selective binding of O2. In contrast with O2 adsorption, N2 adsorption at open metal sites is predicted to be relatively weak across the MOF dataset, with the exception of MOFs containing synthetically elusive V2+ open metal sites. As one example from the screening study, we predict that exchanging the μ-Cl- ligands of M2Cl2(BBTA) (H2BBTA = 1H,5H-benzo(1,2-d:4,5-d′)bistriazole) with μ-OH- groups would significantly enhance the strength of O2 adsorption at the open metal sites without a corresponding increase in the N2 affinity. Experimental investigation of Co2Cl2(BBTA) and Co2(OH)2(BBTA) confirms that the former exhibits only weak physisorption, whereas the latter is capable of chemisorbing O2 at room temperature. The chemisorption behavior is attributed to the greater electron-donating character of the μ-OH- ligands and the presence of H-bonding interactions between the μ-OH- bridging ligands and the O2 adsorbate.

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Including dispersion in density functional theory for adsorption on flat oxide surfaces, in metal–organic frameworks and in acidic zeolites

Physical Chemistry Chemical Physics ◽

10.1039/d0cp00394h ◽

2020 ◽

Vol 22 (14) ◽

pp. 7577-7585 ◽

Cited By ~ 2

Author(s):

Florian R. Rehak ◽

GiovanniMaria Piccini ◽

Maristella Alessio ◽

Joachim Sauer

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Van Der Waals ◽

Metal Organic Frameworks ◽

Many Body ◽

Functional Theory ◽

Metal Organic ◽

The Many ◽

Acidic Zeolites ◽

Better Than

Contrary to common believe, for eight adsorption cases, neither D3 or TS are an improvement compared to D2 nor van der Waals functionals or dDsC. Only the many body approaches are slightly better than D2(Ne) which uses Ne parameters for Mg2+ ions.

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Charge-transfer interactions between fullerenes and a mesoporous tetrathiafulvalene-based metal–organic framework

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.10.183 ◽

2019 ◽

Vol 10 ◽

pp. 1883-1893 ◽

Cited By ~ 1

Author(s):

Manuel Souto ◽

Joaquín Calbo ◽

Samuel Mañas-Valero ◽

Aron Walsh ◽

Guillermo Mínguez Espallargas

Keyword(s):

Electrical Conductivity ◽

Charge Transfer ◽

Density Functional ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Spectroscopic Techniques ◽

Functional Theory ◽

Guest Molecules ◽

Crucial Step ◽

Metal Organic

The design of metal–organic frameworks (MOFs) incorporating electroactive guest molecules in the pores has become a subject of great interest in order to obtain additional electrical functionalities within the framework while maintaining porosity. Understanding the charge-transfer (CT) process between the framework and the guest molecules is a crucial step towards the design of new electroactive MOFs. Herein, we present the encapsulation of fullerenes (C60) in a mesoporous tetrathiafulvalene (TTF)-based MOF. The CT process between the electron-acceptor C60 guest and the electron-donor TTF ligand is studied in detail by means of different spectroscopic techniques and density functional theory (DFT) calculations. Importantly, gas sorption measurements demonstrate that sorption capacity is maintained after encapsulation of fullerenes, whereas the electrical conductivity is increased by two orders of magnitude due to the CT interactions between C60 and the TTF-based framework.

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Investigation of Charge-Transfer Interactions Induced by Encapsulating Fullerene in a Mesoporous Tetrathiafulvalene-Based Metal-Organic Framework

10.26434/chemrxiv.8427047.v1 ◽

2019 ◽

Cited By ~ 1

Author(s):

Manuel Souto ◽

Joaquín Calbo ◽

Samuel Mañas-Valero ◽

Aron Walsh ◽

Guillermo Minguez Espallargas

Keyword(s):

Electrical Conductivity ◽

Charge Transfer ◽

Density Functional ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Density Functional Theory Calculations ◽

Spectroscopic Techniques ◽

Functional Theory ◽

Guest Molecules ◽

Metal Organic

The design of Metal-Organic Frameworks (MOFs) incorporating electroactive guest molecules in the pores has become a subject of great interest in order to install additional electrical functionalities within the framework while maintaining porosity. In this direction, understanding the charge-transfer (CT) process between the framework and the guest molecules is crucial towards the design of new electroactive MOFs. Herein, we present the encapsulation of fullerenes (C60) in a mesoporous tetrathiafulvalene(TTF)-based MOF. The CT process between the electron-acceptor C60 guest and the electron-donor TTF ligand is studied in detail by means of different spectroscopic techniques and density functional theory calculations. Importantly, gas sorption measurements demonstrate that sorption capacity is maintained after encapsulation of fullerenes, whereas the electrical conductivity is increased by two orders of magnitude due to the CT interactions between C60and the TTF-based framework.

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Tuning the Redox Activity of Metal−Organic Frameworks for Enhanced, Selective O2 Binding: Design Rules and Ambient Temperature O2 Chemisorption in a Cobalt−Triazolate Framework

10.26434/chemrxiv.10316681.v2 ◽

2020 ◽

Author(s):

Andrew Rosen ◽

M. Rasel Mian ◽

Timur Islamoglu ◽

Haoyuan Chen ◽

Omar Farha ◽

...

Keyword(s):

Density Functional ◽

Metal Organic Frameworks ◽

Redox Activity ◽

Screening Methods ◽

Bridging Ligands ◽

Metal Centers ◽

Computational Screening ◽

Open Metal Sites ◽

Metal Organic ◽

Unsaturated Metal Sites

Metal−organic frameworks (MOFs) with coordinatively unsaturated metal sites are appealing as adsorbent materials due to their tunable functionality and ability to selectively bind small molecules. Through the use of computational screening methods based on periodic density functional theory, we investigate O2 and N2 adsorption at the coordinatively unsaturated metal sites of several MOF families. A variety of design handles are identified that can be used to modify the redox activity of the metal centers, including changing the functionalization of the linkers (replacing oxido donors with sulfido donors), anion exchange of bridging ligands (considering μ-Br-, μ-Cl-, μ-F-, μ-SH-, or μ-OH- groups), and altering the formal oxidation state of the metal. As a result, we show that it is possible to tune the O2 affinity at the open metal sites of MOFs for applications involving the strong and/or selective binding of O2. In contrast with O2 adsorption, N2 adsorption at open metal sites is predicted to be relatively weak across the MOF dataset, with the exception of MOFs containing synthetically elusive V2+ open metal sites. As one example from the screening study, we predicted that exchanging the μ-Cl- ligands of M2Cl2(BBTA) (H2BBTA = 1H,5H-benzo(1,2-d:4,5-d′)bistriazole) with μ-OH- groups would significantly enhance the strength of O2 adsorption at the open metal sites without a corresponding increase in the N2 affinity. Experimental investigation of Co2Cl2(BBTA) and Co2(OH)2(BBTA) confirms that the former exhibits weak physisorption of both N2 and O2, whereas the latter is capable of chemisorbing O2 at room temperature in a highly selective manner. The O2 chemisorption behavior is attributed to the greater electron-donating character of the μ-OH- ligands and the presence of H-bonding interactions between the μ-OH- bridging ligands and the reduced O2 adsorbate.

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Investigation of Charge-Transfer Interactions Induced by Encapsulating Fullerene in a Mesoporous Tetrathiafulvalene-Based Metal-Organic Framework

10.26434/chemrxiv.8427047 ◽

2019 ◽

Author(s):

Manuel Souto ◽

Joaquín Calbo ◽

Samuel Mañas-Valero ◽

Aron Walsh ◽

Guillermo Minguez Espallargas

Keyword(s):

Electrical Conductivity ◽

Charge Transfer ◽

Density Functional ◽

Metal Organic Framework ◽

Metal Organic Frameworks ◽

Density Functional Theory Calculations ◽

Spectroscopic Techniques ◽

Functional Theory ◽

Guest Molecules ◽

Metal Organic

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Density functional study of hydrogen spillover on direct Pd-doped metal-organic frameworks IRMOF-1

International Journal of Hydrogen Energy ◽

10.1016/j.ijhydene.2011.12.065 ◽

2012 ◽

Vol 37 (6) ◽

pp. 5081-5089 ◽

Cited By ~ 17

Author(s):

Tongyu Wang ◽

Qiuju Zhang ◽

Baihai Li ◽

Hong Chen ◽

Liang Chen

Keyword(s):

Density Functional ◽

Metal Organic Frameworks ◽

Hydrogen Spillover ◽

Functional Study ◽

Density Functional Study ◽

Metal Organic

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Tuning the Redox Activity of Metal−Organic Frameworks for Enhanced, Selective O2 Binding: Design Rules and Ambient Temperature O2 Chemisorption in a Cobalt−Triazolate Framework

10.26434/chemrxiv.10316681 ◽

2020 ◽

Author(s):

Andrew Rosen ◽

M. Rasel Mian ◽

Timur Islamoglu ◽

Haoyuan Chen ◽

Omar Farha ◽

...

Keyword(s):

Density Functional ◽

Metal Organic Frameworks ◽

Redox Activity ◽

Screening Methods ◽

Bridging Ligands ◽

Metal Centers ◽

Computational Screening ◽

Open Metal Sites ◽

Metal Organic ◽

Unsaturated Metal Sites

Metal−organic frameworks (MOFs) with coordinatively unsaturated metal sites are appealing as adsorbent materials due to their tunable functionality and ability to selectively bind small molecules. Through the use of computational screening methods based on periodic density functional theory, we investigate O2 and N2 adsorption at the coordinatively unsaturated metal sites of several MOF families. A variety of design handles are identified that can be used to modify the redox activity of the metal centers, including changing the functionalization of the linkers (replacing oxido donors with sulfido donors), anion exchange of bridging ligands (considering μ-Br-, μ-Cl-, μ-F-, μ-SH-, or μ-OH- groups), and altering the formal oxidation state of the metal. As a result, we show that it is possible to tune the O2 affinity at the open metal sites of MOFs for applications involving the strong and/or selective binding of O2. In contrast with O2 adsorption, N2 adsorption at open metal sites is predicted to be relatively weak across the MOF dataset, with the exception of MOFs containing synthetically elusive V2+ open metal sites. As one example from the screening study, we predicted that exchanging the μ-Cl- ligands of M2Cl2(BBTA) (H2BBTA = 1H,5H-benzo(1,2-d:4,5-d′)bistriazole) with μ-OH- groups would significantly enhance the strength of O2 adsorption at the open metal sites without a corresponding increase in the N2 affinity. Experimental investigation of Co2Cl2(BBTA) and Co2(OH)2(BBTA) confirms that the former exhibits weak physisorption of both N2 and O2, whereas the latter is capable of chemisorbing O2 at room temperature in a highly selective manner. The O2 chemisorption behavior is attributed to the greater electron-donating character of the μ-OH- ligands and the presence of H-bonding interactions between the μ-OH- bridging ligands and the reduced O2 adsorbate.

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Coordinatively unsaturated metal sites (open metal sites) in metal–organic frameworks: design and applications

Chemical Society Reviews ◽

10.1039/c9cs00609e ◽

2020 ◽

Vol 49 (9) ◽

pp. 2751-2798 ◽

Cited By ~ 50

Author(s):

Ülkü Kökçam-Demir ◽

Anna Goldman ◽

Leili Esrafili ◽

Maniya Gharib ◽

Ali Morsali ◽

...

Keyword(s):

Metal Organic Frameworks ◽

Supramolecular Interactions ◽

Guest Molecules ◽

Open Metal Sites ◽

Metal Organic ◽

Unsaturated Metal Sites

The defined synthesis of OMS in MOFs is the basis for targeted functionalization through grafting, the coordination of weakly binding species and increased (supramolecular) interactions with guest molecules.

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Modulating electronic structure of metal-organic frameworks by introducing atomically dispersed Ru for efficient hydrogen evolution

Nature Communications ◽

10.1038/s41467-021-21595-5 ◽

2021 ◽

Vol 12 (1) ◽

Cited By ~ 1

Author(s):

Yamei Sun ◽

Ziqian Xue ◽

Qinglin Liu ◽

Yaling Jia ◽

Yinle Li ◽

...

Keyword(s):

Electronic Structure ◽

Hydrogen Evolution ◽

Hydrogen Evolution Reaction ◽

Density Functional ◽

Metal Organic Frameworks ◽

Catalyst Design ◽

Single Atom ◽

Hydrogen Energy ◽

Structure Of Metal ◽

Metal Organic

AbstractDeveloping high-performance electrocatalysts toward hydrogen evolution reaction is important for clean and sustainable hydrogen energy, yet still challenging. Herein, we report a single-atom strategy to construct excellent metal-organic frameworks (MOFs) hydrogen evolution reaction electrocatalyst (NiRu0.13-BDC) by introducing atomically dispersed Ru. Significantly, the obtained NiRu0.13-BDC exhibits outstanding hydrogen evolution activity in all pH, especially with a low overpotential of 36 mV at a current density of 10 mA cm−2 in 1 M phosphate buffered saline solution, which is comparable to commercial Pt/C. X-ray absorption fine structures and the density functional theory calculations reveal that introducing Ru single-atom can modulate electronic structure of metal center in the MOF, leading to the optimization of binding strength for H2O and H*, and the enhancement of HER performance. This work establishes single-atom strategy as an efficient approach to modulate electronic structure of MOFs for catalyst design.

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