ENHANCEMENT EFFECT OF LITHIUM-DOPING FUNCTIONALIZATION ON HYDROGEN ADSORPTION IN METAL-ORGANIC FRAMEWORK

2016 ◽  
Vol 24 (05) ◽  
pp. 1750067 ◽  
Author(s):  
LIANGZHI XIA ◽  
QING LIU ◽  
FENGLING WANG ◽  
YUPENG LI
Keyword(s):  
Hydrogen Adsorption ◽  
Metal Organic Framework ◽  
Enhancement Effect ◽  
Li Doping ◽  
Adsorption Sites ◽  
Hydrogen Molecules ◽  
Metal Organic ◽  
Gravimetric Adsorption ◽  
Hydrogen Storage Performance ◽  
Grand Canonical

Grand canonical Monte-Carlo simulation was carried out to study the effect of linker functionalization by Li atoms. In this work, two new Li-doping structures, MOF-808-Li and MOF-808-OLi were theoretically constructed by physical modification and chemical modification, respectively. The results show that both these methods can improve the hydrogen storage performance significantly, owing to the Li atoms increasing the interaction energy between the hydrogen molecules and the Li-doped MOF-808. Furthermore, MOF-808-OLi shows higher hydrogen capacity in comparison to the H2 adsorption in the MOF-808-Li, this can be attributed to the new adsorption sites created by oxygen atom. The gravimetric adsorption capacity of MOF-808-OLi can reach 3.17[Formula: see text]wt.% at 77[Formula: see text]K and 1[Formula: see text]bar, which are significantly higher than the hydrogen adsorption in the unmodified MOF-808.

Grand Canonical Monte Carlo Simulations for the Prediction of Adsorption Capacity of Hydrogen in MOFs

2007 ◽  
Vol 124-126 ◽  
pp. 1693-1696 ◽  
Author(s):  
Dong Hyun Jung ◽  
Dae Jin Kim ◽  
Tae Bum Lee ◽  
Ja Heon Kim ◽  
Seung Hoon Choi
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Rational Design ◽  
Hydrogen Adsorption ◽  
Hydrogen Uptake ◽  
Grand Canonical Monte Carlo ◽  
Diverse Range ◽  
Adsorption Sites ◽  
Hydrogen Molecules ◽  
Grand Canonical

We performed grand canonical Monte Carlo simulations on the series of MOFs, that are Metal-Organic Frameworks having various organic linkers and nanocube frameworks, to find out rational design and synthetic strategies toward efficient hydrogen storage materials. The adsorption amounts of hydrogen molecules showed diverse range according to the variation of parameter values. This indicated that the hydrogen adsorption was sensitive to the values of parameters corresponding to the non-bonding interactions. The optimization of the parameters was done to fit the experimental results at 77 K. After the parameterization of the potential function, we adopted this condition to predict the adsorption amount of hydrogen molecules on IRMOF-3, which has NH2 group as the substituent of hydrogen bonded to benzene ring. The calculation results showed good agreement with experimental adsorptions and we analyzed the adsorption sites of each MOF and the relationship between the adsorption characteristics and the hydrogen uptake capacity.

Understanding the Mechanism of Hydrogen Adsorption into Metal-Organic Frameworks

2005 ◽  
Vol 885 ◽  
Author(s):  
Tae-Bum Lee ◽  
Daejin Kim ◽  
Seung-Hoon Choi ◽  
Ji Hye Yoon ◽  
Sang Beom Choi ◽  
...  
Keyword(s):  
Benzene Ring ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Density Functional Theory Calculation ◽  
Metal Organic Frameworks ◽  
Geometry Optimization ◽  
Porous Metal ◽  
Adsorption Sites ◽  
Hydrogen Molecules ◽  
Metal Organic

ABSTRACTHydrogen adsorption mechanism into the porous metal-organic frameworks (MOFs) has been studied by density functional theory calculation. The selected functionals for the prediction of interaction energies between hydrogen and potential adsorption sites of MOFs were utilized after the evaluation with the various functionals for interaction energy of H2···C6H6 model system. The adsorption energy of hydrogen molecule into MOFs was investigated with the consideration of the favorable adsorption sites and the orientations. We also calculated the second favorable adsorption sites by geometry optimization using every combination of two first absorbed hydrogen molecules. Based on the calculation of first and second adsorption sites and energies, it has been suggested that the hydrogen adsorption into MOFs follows a cooperative mechanism in which the initial metal sites initiate the propagation of the hydrogen adsorption on the whole frameworks. In addition, the interaction mode between the simple benzene ring with hydrogen is significantly changed when the benzene ring has been incorporated into the framework of MOFs.

Peculiarities of high-pressure hydrogen adsorption on Pt catalyzed Cu-BTC metal–organic framework

2021 ◽  
Vol 23 (7) ◽  
pp. 4277-4286
Author(s):  
S. V. Chuvikov ◽  
E. A. Berdonosova ◽  
A. Krautsou ◽  
J. V. Kostina ◽  
V. V. Minin ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Hydrogen Adsorption ◽  
Metal Organic Framework ◽  
Pt Catalyst ◽  
Metal Organic ◽  
Pt Catalyzed ◽  
Pressure Hydrogen ◽  
Organic Framework

Pt-Catalyst plays a key role in hydrogen adsorption by Cu-BTC at high pressures.

Enhancement of Carbon Dioxide Adsorption by Lithium Decorating and Fullerene Encapsulating in Metal-Organic Frameworks

2013 ◽  
Vol 773 ◽  
pp. 927-931
Author(s):  
Rui Feng Lu ◽  
De Wei Rao ◽  
Zhao Shun Meng ◽  
Kai Ming Deng
Keyword(s):  
Metal Organic Frameworks ◽  
Carbon Dioxide Adsorption ◽  
Grand Canonical Monte Carlo ◽  
Ambient Conditions ◽  
Li Doping ◽  
Lithium Doping ◽  
Crystal Density ◽  
Metal Organic ◽  
Density Surface ◽  
Grand Canonical

Using grand canonical Monte Carlo method, the capacities of CO2adsorption in IRMOF-12 and-14 are simulated at ambient conditions. We have theoretically found that CO2uptake can be greatly enhanced by either lithium doping or fullerene impregnating, and the influence of the Li doping is more significant than that of C60impregnation. Furthermore, the CO2storage capacities of IRMOFs after both Li doping and C60impregnating are improved to be about 30 times those of corresponding pristine structures. To further understand the mechanism, we analyzed the distribution pattern of CO2adsorption in materials and investigated the relationships between CO2uptakes and crystal density, surface area per volume and per mass, and pore volume per volume and per mass in detail.

A 2D porous Pb-MOF based on 2-nitroimidazole: CO2 adsorption, electronic structure and luminescence

2021 ◽  
Author(s):  
Xiu-Yuan Li ◽  
Wang Ying-Bo ◽  
Song Yan ◽  
Xiang Dan ◽  
Chaozheng He
Keyword(s):  
Electronic Structure ◽  
Electronic Structures ◽  
Metal Ion ◽  
Co2 Adsorption ◽  
Metal Organic Framework ◽  
Porous Metal ◽  
Adsorption Sites ◽  
Porous Framework ◽  
Metal Organic ◽  
Gcmc Simulations

Abstract A new porous metal-organic framework, [Pb5(Ac)7(nIm)3]n (1), has been successfully synthesized by employing 2-nitroimidazole ligand and Pb2+ ion. 1 contains novel the ribbon-shaped Pb-O SBU and reveals a 2D porous framework with a 1D tubular channel. Moreover, 1 shows moderate adsorption uptake towards CO2 and luminescence properties from intraligand charge transfer. We further confirmed nitro group and metal ion are important adsorption sites by GCMC simulations, and the electronic structures of 1 was investigated.

Investigation, using density function theory, of coverage of the kaolinite (001) surface during hydrogen adsorption

Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 393-402 ◽  
Author(s):  
Jian Zhao ◽  
Wei Gao ◽  
Zhi-Gang Tao ◽  
Hong-Yun Guo ◽  
Man-Chao He
Keyword(s):  
Density Functional ◽  
Hydrogen Adsorption ◽  
Function Theory ◽  
Lattice Relaxation ◽  
Electronic Density ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Coverage Dependence ◽  
Hydrogen Molecules ◽  
Wide Range

ABSTRACTKaolinite can be used for many applications, including the underground storage of gases. Density functional theory was employed to investigate the adsorption of hydrogen molecules on the kaolinite (001) surface. The coverage dependence of the adsorption sites and energetics was studied systematically for a wide range of coverage, Θ (from 1/16 to 1 monolayer). The three-fold hollow site is the most stable, followed by the bridge, top-z and top sites. The adsorption energy of H2 decreased with increasing coverage, thus indicating the lower stability of surface adsorption due to the repulsion of neighbouring H2 molecules. The coverage has obvious effects on hydrogen adsorption. Other properties of the H2/kaolinite (001) system, including the lattice relaxation and changes of electronic density of states, were also studied and are discussed in detail.

scholarly journals Statistical Thermodynamic Model of Gas Adsorption in a Metal-Organic Framework Harboring a Rotaxane Molecular Shuttle

2019 ◽  
Author(s):  
Jonathan Carney ◽  
David Roundy ◽  
Cory M. Simon
Keyword(s):  
Thermodynamic Model ◽  
Gas Adsorption ◽  
Metal Organic Framework ◽  
Adsorption Properties ◽  
Statistical Thermodynamic ◽  
Temperature Sensitive ◽  
Adsorption Sites ◽  
Metal Organic ◽  
Dynamic Components ◽  
Molecular Shuttle

Metal-organic frameworks (MOFs) are modular and adjustable nano-porous materials with applications in gas storage, separations, and sensing. Flexible/dynamic components that respond to adsorbed gas can give MOFs unique or enhanced adsorption properties. Here, we explore the adsorption properties that could be imparted to a MOF by a rotaxane molecular shuttle (RMS) in its pores. In an RMS-MOF, a macrocyclic wheel is mechanically interlocked with a strut. The wheel shuttles between stations on the strut that are also gas adsorption sites. We pose and analyze a simple statistical thermodynamic model of gas adsorption in an RMS-MOF that accounts for (i) wheel/gas competition for sites on the strut and (ii) the entropy endowed by the shuttling wheel. We determine how the amount of gas adsorbed, position of the wheel, and energy change upon adsorption depend on temperature, pressure, and the interactions of the gas/wheel with the stations. Our model reveals that, compared to an ordinary Langmuir material, the chemistry of the RMS-MOF can be tuned to render adsorption more or less temperature-sensitive and release more or less heat upon adsorption. The model also uncovers a non-monotonic relationship between temperature and the position of the wheel if gas out-competes the wheel for its preferable station.

A zwitterionic metal–organic framework with free carboxylic acid sites that exhibits enhanced hydrogen adsorption energies

CrystEngComm ◽  
2013 ◽  
Vol 15 (45) ◽  
pp. 9408 ◽  
Author(s):  
Marianne B. Lalonde ◽  
Rachel B. Getman ◽  
Jeong Yong Lee ◽  
John M. Roberts ◽  
Amy A. Sarjeant ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Hydrogen Adsorption ◽  
Metal Organic Framework ◽  
Acid Sites ◽  
Metal Organic ◽  
Adsorption Energies ◽  
Organic Framework

scholarly journals CO2 Adsorption in Metal-Organic Framework Mg-MOF-74: Effects of Inter-Crystalline Space

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2274
Author(s):  
Siddharth Gautam ◽  
David Cole
Keyword(s):  
Metal Organic Framework ◽  
Co2 Storage ◽  
Volume Ratio ◽  
Chem Phys ◽  
Crystallite Sizes ◽  
Metal Organic ◽  
Adsorption Of Co2 ◽  
Gcmc Simulations ◽  
Grand Canonical ◽  
The Ideal

Metal-Organic Frameworks (MOF) have been identified as highly efficient nanoporous adsorbents for CO2 storage. In particular, Mg-MOF-74 has been shown to promise exceptionally high CO2 sorption. Although several studies have reported adsorption isotherms of CO2 in Mg-MOF-74, the effect of inter-crystalline spacing in Mg-MOF-74 on the sorption of CO2 has not been addressed. These effects have been shown to be profound for a quadrupolar molecule like CO2 in the case of silicalite (Phys. Chem. Chem. Phys. 22 (2020) 13951). Here, we report the effects of inter-crystalline spacing on the adsorption of CO2 in Mg-MOF-74, studied using grand canonical Monte Carlo (GCMC) simulations. The inter-crystalline spacing is found to enhance adsorption at the crystallite surfaces. Larger inter-crystalline spacing up to twice the kinetic diameter of CO2 results in higher adsorption and larger crystallite sizes suppress adsorption. Magnitudes of the inter-crystalline space relative to the kinetic diameter of the adsorbed fluid and the surface to volume ratio of the adsorbent crystallites are found to be important factors determining the adsorption amounts. The results of this study suggest that the ideal Mg-MOF-74 sample for CO2 storage applications should have smaller crystallites separated from each other with an inter-crystalline space of approximately twice the kinetic diameter of CO2.

Sign in / Sign up

Export Citation Format

Share Document