Effect of temperature on gas adsorption and separation in ZIF-8: A combined experimental and molecular simulation study

doi:10.1016/j.ces.2011.09.009

Chemical Engineering Science

Volume 66, Issue 23, 1 December 2011, Pages 6297-6305

https://doi.org/10.1016/j.ces.2011.09.009 Get rights and content

Abstract

In this work, the effect of temperature on adsorption of CO₂, CH₄, CO, and N₂ and separation of their binary mixtures in ZIF-8 were investigated using experimental measurements combining with molecular simulations. The results show that for pure gas adsorption, the effect of temperature is large when strong adsorption occurs, mainly due to the variation of the interaction energy between adsorbate molecules with temperature; while for gas mixtures, systems with large selectivity are more sensitive to temperature. In addition, this work shows that temperature influences the working capacity of CO₂ in temperature swing adsorption (TSA) process with the interplay of pressure, which should be considered in the design of TSA process in practical applications.

Highlights

► A combined experimental and simulation study on effect of temperature on gas adsorption and separation in ZIF-8. ► For pure gases with large isosteric heat of adsorption, the effect of temperature is large. ► For gas mixtures, systems with large selectivity are more sensitive to temperature. ► Temperature influences the working capacity of CO₂ with the interplay of pressure.

Introduction

Metal-organic frameworks (MOFs), as a new family of nanoporous materials, have been developed into one of the most fruitful research areas in chemistry and materials (Kitagawa et al., 2004, Rowsell and Yaghi, 2004, Férey, 2008, Long and Yaghi, 2009). They exhibit unique advantages over other traditional porous materials like carbonaceous materials and zeolites, due to the fine-tunable pore structures and adjustable chemical functionality. From an industrial point of view, gas separation is one of the most promising fields that first practical application of MOFs may be applied to (Mueller et al., 2006, Czaja et al., 2009).

Recently, a subclass of MOFs named zeolitic imidazolate frameworks (ZIFs) emerged, which has tetrahedral networks that resemble those of zeolites with transition metals (Co, Cu, Zn, etc.) linked by imidazolate ligands (Park et al., 2006, Hayashi et al., 2007, Banerjee et al., 2008, Banerjee et al., 2009, Wang et al., 2008). ZIFs show exceptional chemical and thermal stability (Park et al., 2006, Küsgens et al., 2009), which is crucial for the industrial applications of MOFs. Thus, increasing interests have been paid to gas separation (Liu and Smit, 2010, Nalaparaju et al., 2010, Guo et al., 2010, Keskin, 2011) in ZIFs recently, demonstrating that ZIFs are potential candidates in many practical operations, such as the pressure swing adsorption (PSA), temperature swing adsorption (TSA) and membrane separation (Venna and Carreon, 2010, Bux et al., 2009, Yao et al., 2011, McCarthy et al., 2010). In these processes, temperature may play an important role on the separation performance of absorbents. However, little is known about how temperature influences the adsorption selectivities for different gas mixtures in ZIFs, which is important in the practical applications of ZIFs. Therefore, in this work the adsorption behavior of several industrially important gases as well as the adsorption selectivity and working capacity of their binary mixtures in ZIF-8 at different temperatures were systematically investigated, using a combined experimental and molecular simulation method. The information obtained is expected to provide useful information for the extensive practical applications of ZIFs in industry.

Section snippets

Experimental method

ZIF-8 was obtained from Sigma-Aldrich, and the structure of the sample was confirmed by comparing the PXRD patterns with the published results (Yazaydın et al., 2009) (see Supplementary Information).

Gas sorption experiments were carried out on Autosorb-iQ-MP (Quantachrome Instruments) by measuring the increase of volume at equilibrium as a function of the relative pressure. Sample weights were measured using a Sartorius BS-124S electrogravimetric balance (sensitivity 0.1 mg). 50 mg ZIF-8 sample

Effect of temperature on adsorption isotherms of single component in ZIF-8

The adsorption isotherms of CO₂, CH₄, CO, and N₂ in ZIF-8 were measured at 273, 298, 323, and 348 K, respectively, as presented in Fig. 1. It is obvious that the adsorption amounts for the single component all decreases with increasing temperature. Recently, several other groups have also reported experimental adsorption isotherms in ZIF-8, and the comparison with their results are given in Fig. S3. Generally speaking, our data agree well with those of Pérez-Pellitero et al. (2010) and Nune et

Conclusions

This work shows that the effect of temperature on gas adsorption and separation is system-dependent. For pure gases with large isosteric heat of adsorption, the effect of temperature is large, which is mainly due to the variation of the interaction energy between adsorbate molecules with temperature; for gas mixtures, systems with large selectivity are more sensitive to temperature. Furthermore, it is found that temperature influences the working capacity of CO₂ in TSA technology with the

Acknowledgments

This work was supported by the Natural Science Foundation of China (Nos.: 20725622, 20821004, 20925623, 21136001). B. L. thanks the Research Funds of China University of Petroleum, Beijing (BJBJRC-2010-01).

References (46)

A. Battisti et al.
Zeolitic imidazolate frameworks for separation of binary mixtures of CO₂, CH₄, N₂ and H₂: a computer simulation investigation
Micropor. Mesopor. Mater.
(2011)
T.C. Drage et al.
Developing strategies for the regeneration of polyethylenimine based CO₂ adsorbents
Energy Procedia
(2009)
R. Krishna et al.
In silico screening of zeolite membranes for CO₂ capture
J. Membr. Sci
(2010)
P. Küsgens et al.
Characterization of metal-organic frameworks by water adsorption
Micropor. Mesopor. Mater.
(2009)
J.L.C. Rowsell et al.
Metal-organic frameworks: a new class of porous materials
Micropor. Mesopor. Mater.
(2004)
J.E. Straub et al.
Molecular dynamics study of the photodissociation of carbon monoxide from myoglobin: ligand dynamics in the first 10 ps
Chem. Phys.
(1991)
R. Banerjee et al.
Control of pore size and functionality in isoreticular zeolitic imidazolate frameworks and their carbon dioxide selective capture properties
J. Am. Chem. Soc.
(2009)
R. Banerjee et al.
High-throughput synthesis of zeolitic imidazolate frameworks and application to CO₂ capture
Science
(2008)
H. Bux et al.
Zeolitic imidazolate framework membrane with molecular sieving properties by microwave-assisted solvothermal synthesis
J. Am. Chem. Soc.
(2009)
Y. Chen et al.
A highly hydrophobic metal-organic framework Zn(BDC)(TED)_0.5 for adsorption and separation of CH₃OH/H₂O and CO₂/CH₄: an integrated experimental and simulation study
J. Phys. Chem. C
(2010)

A.U. Czaja et al.

Industrial applications of metal-organic frameworks

Chem. Soc. Rev.

(2009)

D.D. Do et al.

Modeling of adsorption on nongraphitized carbon surface: GCMC simulation studies and comparison with experimental data

J. Phys. Chem. B

(2006)

Fairen-Jimenez, D., Lozano-Casal, P., Duren, T., 2008. Assessing generic force fields to describe adsorption on...

D. Fairen-Jimenez et al.

Opening the gate: framework flexibility in ZIF-8 explored by experiments and simulations

J. Am. Chem. Soc.

(2011)

G. Férey

Hybrid porous solids: past, present, future

Chem. Soc. Rev.

(2008)

D. Frenkel et al.

Understanding Molecular Simulation: From Algorithms to Applications

(2002)

H. Frost et al.

Design requirements for metal-organic frameworks as hydrogen storage materials

J. Phys. Chem. C

(2007)

H. Guo et al.

Molecular simulation for adsorption and separation of CH₄/H₂ in zeolitic imidazolate frameworks

J. Phys. Chem. C

(2010)

H. Hayashi et al.

Zeolite A imidazolate frameworks

Nat. Mater.

(2007)

S. Keskin

Atomistic simulations for adsorption, diffusion, and separation of gas mixtures in zeolite imidazolate frameworks

J. Phys. Chem. C

(2011)

S. Kitagawa et al.

Functional porous coordination polymers

Angew. Chem. Int. Ed.

(2004)

R. Krishna et al.

Hydrogen bonding effects in adsorption of water–alcohol mixtures in zeolites and the consequences for the characteristics of the Maxwell–Stefan diffusivities

Langmuir

(2010)

B. Liu et al.

Enhanced adsorption selectivity of hydrogen/methane mixtures in metal-organic frameworks with interpenetration: a molecular simulation study

J. Phys. Chem. C

(2008)

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Effect of temperature on gas adsorption and separation in ZIF-8: A combined experimental and molecular simulation study

Abstract

Highlights

Introduction

Section snippets

Experimental method

Effect of temperature on adsorption isotherms of single component in ZIF-8

Conclusions

Acknowledgments

Micropor. Mesopor. Mater.

Energy Procedia

J. Membr. Sci

Micropor. Mesopor. Mater.

Micropor. Mesopor. Mater.

Chem. Phys.

Control of pore size and functionality in isoreticular zeolitic imidazolate frameworks and their carbon dioxide selective capture properties

J. Am. Chem. Soc.

High-throughput synthesis of zeolitic imidazolate frameworks and application to CO2 capture

Science

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J. Am. Chem. Soc.

A highly hydrophobic metal-organic framework Zn(BDC)(TED)0.5 for adsorption and separation of CH3OH/H2O and CO2/CH4: an integrated experimental and simulation study

J. Phys. Chem. C

Industrial applications of metal-organic frameworks

Chem. Soc. Rev.

Modeling of adsorption on nongraphitized carbon surface: GCMC simulation studies and comparison with experimental data

J. Phys. Chem. B

Opening the gate: framework flexibility in ZIF-8 explored by experiments and simulations

J. Am. Chem. Soc.

Hybrid porous solids: past, present, future

Chem. Soc. Rev.

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Design requirements for metal-organic frameworks as hydrogen storage materials

J. Phys. Chem. C

Molecular simulation for adsorption and separation of CH4/H2 in zeolitic imidazolate frameworks

J. Phys. Chem. C

Zeolite A imidazolate frameworks

Nat. Mater.

Atomistic simulations for adsorption, diffusion, and separation of gas mixtures in zeolite imidazolate frameworks

J. Phys. Chem. C

Functional porous coordination polymers

Angew. Chem. Int. Ed.

Hydrogen bonding effects in adsorption of water–alcohol mixtures in zeolites and the consequences for the characteristics of the Maxwell–Stefan diffusivities

Langmuir

Enhanced adsorption selectivity of hydrogen/methane mixtures in metal-organic frameworks with interpenetration: a molecular simulation study

J. Phys. Chem. C

High-throughput synthesis of zeolitic imidazolate frameworks and application to CO₂ capture

A highly hydrophobic metal-organic framework Zn(BDC)(TED)_0.5 for adsorption and separation of CH₃OH/H₂O and CO₂/CH₄: an integrated experimental and simulation study

Molecular simulation for adsorption and separation of CH₄/H₂ in zeolitic imidazolate frameworks