Influence of Metal Substitution on the Pressure-Induced Phase Change in Flexible Zeolitic Imidazolate Frameworks

2018 ◽  
Author(s):  
C. Michael McGuirk ◽  
Tomče Runčevski ◽  
Julia Oktawiec ◽  
Ari Turkiewicz ◽  
mercedes K. taylor ◽  
...  
Keyword(s):  
Phase Change ◽  
Single Crystal ◽  
Gas Adsorption ◽  
High Capacity ◽  
Phase Changes ◽  
Zeolitic Imidazolate Frameworks ◽  
Metal Substitution ◽  
Heat Management ◽  
Metal Organic ◽  
First Time

<p>Metal–organic frameworks that display step-shaped adsorption profiles arising from discrete pressure-induced phase changes are promising materials for applications in both high-capacity gas storage and energy-efficient gas separations. The thorough investigation of such materials through chemical diversification, gas adsorption measurements, and <i>in situ </i>structural characterization is therefore crucial for broadening their utility. We examine a series of isoreticular, flexible zeolitic imidazolate frameworks (ZIFs) of the type M(bim)<sub>2</sub> (SOD; M = Zn<sup> </sup>(ZIF-7), Co (ZIF-9), Cd (CdIF-13); bim<sup>–</sup> = benzimidazolate), and elucidate the effects of metal substitution on the pressure-responsive phase changes and the resulting CO<sub>2</sub> and CH<sub>4</sub> step positions, pre-step uptakes, and step capacities. Using ZIF-7 as a benchmark, we reexamine the poorly understood structural transition responsible for its adsorption steps and, through high-pressure adsorption measurements, verify that it displays a step in its CH<sub>4 </sub>adsorption isotherms. The ZIF-9 material is shown to undergo an analogous phase change, yielding adsorption steps for CO<sub>2</sub> and CH<sub>4</sub> with similar profiles and capacities to ZIF-7, but with shifted threshold pressures. Further, the Cd<sup>2+</sup> analogue CdIF-13 is reported here for the first time, and shown to display adsorption behavior distinct from both ZIF-7 and ZIF-9, with negligible pre-step adsorption, a ~50% increase in CO<sub>2</sub> and CH<sub>4</sub> capacity, and dramatically higher threshold adsorption pressures. Remarkably, a single-crystal-to-single-crystal phase change to a pore-gated phase is also achieved with CdIF-13, providing insight into the phase change that yields step-shaped adsorption in these flexible ZIFs. Finally, we show that the endothermic phase change of these frameworks provides intrinsic heat management during gas adsorption. </p>

Influence of Metal Substitution on the Pressure-Induced Phase Change in Flexible Zeolitic Imidazolate Frameworks

2018 ◽  
Author(s):  
C. Michael McGuirk ◽  
Tomče Runčevski ◽  
Julia Oktawiec ◽  
Ari Turkiewicz ◽  
mercedes K. taylor ◽  
...  
Keyword(s):  
Phase Change ◽  
Single Crystal ◽  
Gas Adsorption ◽  
High Capacity ◽  
Phase Changes ◽  
Zeolitic Imidazolate Frameworks ◽  
Metal Substitution ◽  
Heat Management ◽  
Metal Organic ◽  
First Time

<p>Metal–organic frameworks that display step-shaped adsorption profiles arising from discrete pressure-induced phase changes are promising materials for applications in both high-capacity gas storage and energy-efficient gas separations. The thorough investigation of such materials through chemical diversification, gas adsorption measurements, and <i>in situ </i>structural characterization is therefore crucial for broadening their utility. We examine a series of isoreticular, flexible zeolitic imidazolate frameworks (ZIFs) of the type M(bim)<sub>2</sub> (SOD; M = Zn<sup> </sup>(ZIF-7), Co (ZIF-9), Cd (CdIF-13); bim<sup>–</sup> = benzimidazolate), and elucidate the effects of metal substitution on the pressure-responsive phase changes and the resulting CO<sub>2</sub> and CH<sub>4</sub> step positions, pre-step uptakes, and step capacities. Using ZIF-7 as a benchmark, we reexamine the poorly understood structural transition responsible for its adsorption steps and, through high-pressure adsorption measurements, verify that it displays a step in its CH<sub>4 </sub>adsorption isotherms. The ZIF-9 material is shown to undergo an analogous phase change, yielding adsorption steps for CO<sub>2</sub> and CH<sub>4</sub> with similar profiles and capacities to ZIF-7, but with shifted threshold pressures. Further, the Cd<sup>2+</sup> analogue CdIF-13 is reported here for the first time, and shown to display adsorption behavior distinct from both ZIF-7 and ZIF-9, with negligible pre-step adsorption, a ~50% increase in CO<sub>2</sub> and CH<sub>4</sub> capacity, and dramatically higher threshold adsorption pressures. Remarkably, a single-crystal-to-single-crystal phase change to a pore-gated phase is also achieved with CdIF-13, providing insight into the phase change that yields step-shaped adsorption in these flexible ZIFs. Finally, we show that the endothermic phase change of these frameworks provides intrinsic heat management during gas adsorption. </p>

In situ growth and optical gas adsorption performance of Zn(ii) metal–organic framework membranes at room temperature

The Analyst ◽  
2019 ◽  
Vol 144 (16) ◽  
pp. 4887-4896 ◽  
Author(s):  
Mariyemu Tuergong ◽  
Patima Nizamidin ◽  
Abliz Yimit ◽  
Rena Simayi
Keyword(s):  
Room Temperature ◽  
Gas Adsorption ◽  
Uv Light ◽  
Metal Organic Framework ◽  
Adsorption Behaviors ◽  
Uv Light Irradiation ◽  
Unit Surface ◽  
Metal Organic ◽  
First Time

The optical gas adsorption behaviors of [Zn2(bdc)2(dpNDI)]n membranes were studied for the first time. Under UV light irradiation, they exhibited a greater adsorption response to xylene gas with adsorption capacity of 6.46 μg cm−2 per unit surface.

Surfactant-assisted Fabrication and Supercapacitor Performances of 12-phosphomolybdate-pillared Metal-Organic Framework Containing Helix and its SWNT Nanocomposites

CrystEngComm ◽  
2021 ◽  
Author(s):  
Jinlong Zhuo ◽  
Yunliang Wang ◽  
Yu-Guang Wang ◽  
Mingqi Xu ◽  
Jing-Quan Sha
Keyword(s):  
Single Crystal ◽  
Hydrothermal Method ◽  
Metal Organic Framework ◽  
Crystalline Compound ◽  
X Ray ◽  
Metal Organic ◽  
First Time ◽  
Surfactant Assisted ◽  
Organic Framework

A new polyoxometalate-pillared metal-organic framework crystalline compound with multi-fold helical chains, [Ni7(1,2,4-Tri)12(H2O)10][HPMo12O40]·10H2O (NiPMo12), was successfully synthesized by surfactant-assisted hydrothermal method for the first time and characterized by single crystal X-ray...

Influence of Metal Substitution on the Pressure-Induced Phase Change in Flexible Zeolitic Imidazolate Frameworks

2018 ◽  
Vol 140 (46) ◽  
pp. 15924-15933 ◽  
Author(s):  
C. Michael McGuirk ◽  
Tomče Runčevski ◽  
Julia Oktawiec ◽  
Ari Turkiewicz ◽  
Mercedes K. Taylor ◽  
...  
Keyword(s):  
Phase Change ◽  
Zeolitic Imidazolate Frameworks ◽  
Metal Substitution

scholarly journals Emergence of Cooperative Rotor Dynamics in Metal–organic Frameworks via Tuned Steric Interactions

2020 ◽  
Author(s):  
Adrian Gonzalez-Nelson ◽  
Srinidhi Mula ◽  
Mantas Simenas ◽  
Sergejus Balčiūnas ◽  
Adam R. Altenhof ◽  
...  
Keyword(s):  
Gas Adsorption ◽  
Metal Organic Frameworks ◽  
Rotor Dynamics ◽  
Rotational Dynamics ◽  
Crystalline Lattice ◽  
Steric Interactions ◽  
Cooperative Motion ◽  
Metal Organic ◽  
First Time ◽  
Kinetics Of

The organic components in metal-organic frameworks (MOFs) enjoy a unique situation: they are embedded in a crystalline lattice, yet, as they are separated from each other by tunable free space, a large variety of dynamic behavior can emerge. These rotational dynamics of the organic linkers are especially important due to their influence over properties such as gas adsorption and kinetics of guest release. In order to fully exploit linker rotation, it is necessary to engineer correlated linker dynamics to achieve their cooperative functional motion. Here, we show that for MIL-53, a topology with closely spaced rotors, the phenylene functionalization allows to tune the rotors’ steric environment, shifting linker rotation from completely static to rapid motions at frequencies above 100 MHz. For steric interactions that start to inhibit independent rotor motion, we identify for the first time the emergence of correlated rotation modes in linker dynamics. These findings pave the way for function-specific engineering of gearlike cooperative motion in MOFs.

scholarly journals Charting the Complete Thermodynamic Landscape of Gas Adsorption for a Responsive Metal-Organic Framework

2021 ◽  
Author(s):  
Ruben Goeminne ◽  
Simon Krause ◽  
Stefan Kaskel ◽  
Toon Verstraelen ◽  
Jack D. Evans
Keyword(s):  
Gas Adsorption ◽  
Metal Organic Framework ◽  
Thermodynamic Description ◽  
Separation Processes ◽  
Metal Organic ◽  
Complex Landscape ◽  
Thermodynamic Driving Force ◽  
Free Energy Landscapes ◽  
First Time ◽  
Conformational Free Energy

<div>New nanoporous materials are able to revolutionize adsorption and separation processes. In particular, materials with adaptive cavities have high selectivity and may display previously undiscovered phenomena, such as negative gas adsorption (NGA), in which gas is released from the framework upon an increase in pressure. Although the thermodynamic driving force behind this and many other counterintuitive adsorption phenomena have been thoroughly investigated in recent years, several experimental observations remain difficult to explain. This necessitates a comprehensive analysis of gas adsorption akin to the conformational free energy landscapes used to understand the function of proteins. For the first time, we constructed the complete thermodynamic landscape of methane adsorption on DUT-49, a system that demonstrates NGA. Traversing this complex landscape correctly reproduces the experimentally observed structural transitions, the temperature dependence of the NGA phenomenon and the observed hysteresis between adsorption and desorption. The complete thermodynamic description presented here provides unparalleled insight into the process of adsorption and provides a framework to understand other adsorbents that challenge our preconceptions.<br></div>

scholarly journals Emergence of Cooperative Rotor Dynamics in Metal–organic Frameworks via Tuned Steric Interactions

2020 ◽  
Author(s):  
Adrian Gonzalez-Nelson ◽  
Srinidhi Mula ◽  
Mantas Simenas ◽  
Sergejus Balčiūnas ◽  
Adam R. Altenhof ◽  
...  
Keyword(s):  
Gas Adsorption ◽  
Metal Organic Frameworks ◽  
Rotor Dynamics ◽  
Rotational Dynamics ◽  
Crystalline Lattice ◽  
Steric Interactions ◽  
Cooperative Motion ◽  
Metal Organic ◽  
First Time ◽  
Kinetics Of

The organic components in metal-organic frameworks (MOFs) enjoy a unique situation: they are embedded in a crystalline lattice, yet, as they are separated from each other by tunable free space, a large variety of dynamic behavior can emerge. These rotational dynamics of the organic linkers are especially important due to their influence over properties such as gas adsorption and kinetics of guest release. In order to fully exploit linker rotation, it is necessary to engineer correlated linker dynamics to achieve their cooperative functional motion. Here, we show that for MIL-53, a topology with closely spaced rotors, the phenylene functionalization allows to tune the rotors’ steric environment, shifting linker rotation from completely static to rapid motions at frequencies above 100 MHz. For steric interactions that start to inhibit independent rotor motion, we identify for the first time the emergence of correlated rotation modes in linker dynamics. These findings pave the way for function-specific engineering of gearlike cooperative motion in MOFs.

scholarly journals Emergence of Cooperative Rotor Dynamics in Metal–organic Frameworks via Tuned Steric Interactions

2020 ◽  
Author(s):  
Adrian Gonzalez-Nelson ◽  
Srinidhi Mula ◽  
Mantas Simenas ◽  
Sergejus Balčiūnas ◽  
Adam R. Altenhof ◽  
...  
Keyword(s):  
Gas Adsorption ◽  
Metal Organic Frameworks ◽  
Rotor Dynamics ◽  
Rotational Dynamics ◽  
Crystalline Lattice ◽  
Steric Interactions ◽  
Cooperative Motion ◽  
Metal Organic ◽  
First Time ◽  
Kinetics Of

The organic components in metal-organic frameworks (MOFs) enjoy a unique situation: they are embedded in a crystalline lattice, yet, as they are separated from each other by tunable free space, a large variety of dynamic behavior can emerge. These rotational dynamics of the organic linkers are especially important due to their influence over properties such as gas adsorption and kinetics of guest release. In order to fully exploit linker rotation, it is necessary to engineer correlated linker dynamics to achieve their cooperative functional motion. Here, we show that for MIL-53, a topology with closely spaced rotors, the phenylene functionalization allows to tune the rotors’ steric environment, shifting linker rotation from completely static to rapid motions at frequencies above 100 MHz. For steric interactions that start to inhibit independent rotor motion, we identify for the first time the emergence of correlated rotation modes in linker dynamics. These findings pave the way for function-specific engineering of gearlike cooperative motion in MOFs.

Structural and Raman spectroscopic characterization of pyroxene-type compounds in the CaCu1−xZnxGe2O6solid-solution series

2017 ◽  
Vol 73 (3) ◽  
pp. 419-431 ◽  
Author(s):  
Günther J. Redhammer ◽  
Gerold Tippelt ◽  
Andreas Reyer ◽  
Reinhard Gratzl ◽  
Andreas Hiederer
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
Phase Change ◽  
Single Crystal ◽  
Spectroscopic Characterization ◽  
Phase Changes ◽  
Solid Solution Series ◽  
Teller Distortion ◽  
Cell Parameters ◽  
Solution Series

Pyroxene-type germanate compounds with the composition CaCuGe2O6–CaZnGe2O6have been synthesizedviaa solid-state ceramic sintering route. Phase-pure polycrystalline and small single-crystal material was obtained all over the series, representing a complete solid-solution series. Differential thermal analysis, single-crystal X-ray diffraction and Raman spectroscopy were used to characterize phase stability, phase changes and structural alterations induced by the substitution of Cu2+with Zn2+. Whereas pure CaCuGe2O6exhibitsP21/csymmetry with a strong distortion of theM1 octahedra and two different Ge sites, one of them with an unusual fivefold coordination, the replacement of Cu2+by Zn2+induces a chemically driven phase change to theC2/csymmetry. The phase change takes place around Zn2+contents of 0.12 formula units and is associated with large changes in the unit-cell parameters. Here, the increase ofcby as much as 3.2% is remarkable and it is mainly controlled by an expansion of the tetrahedral chains. Further differences between theP21/candC2/cstructures are a more regular chain of edge-sharingM1 octahedra as a consequence of more and more reduced Jahn–Teller distortion and a less kinked, symmetry-equivalent tetrahedral chain. The coordination of the Ca site increases from sevenfold to eightfold with large changes in the Ca—O bond lengths during the phase change. Raman spectroscopy was mainly used to monitor theP21/ctoC2/cphase change as a function of composition, but also as a function of temperature and to follow changes in specific Raman modes throughout the solid-solution series.

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