Adsorption of gases and vapors on nanoporous Ni-2(4,4 '-bipyridine)(3)(NO3)(4) metal-organic framework materials templated with methanol and ethanol: Structural effects in adsorption kinetics

A.J. Fletcher, E.J. Cussen, D. Bradshaw, M.J. Rosseinsky, K.M. Thomas

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Abstract

Desolvation of Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2CH(3)OH and Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2C(2)H(5)OH give flexible metal-organic porous structures M and E, respectively, which have the same stoichiometry, but subtly different structures. This study combines measurements of the thermodynamics and kinetics of carbon dioxide, methanol, and ethanol sorption on adsorbents M and E over a range of temperatures with adsorbent structural characterization at different adsorbate (guest) loadings. The adsorption kinetics for methanol and ethanol adsorption on porous structure E obey a linear driving force (LDF) mass transfer model for adsorption at low surface coverage. The corresponding adsorption kinetics for porous structure M follow a double exponential (DE) model, which is consistent with two different barriers for diffusion through the windows and along the pores in the structure. The former is a high-energy barrier due to the opening of the windows in the structure, required to allow adsorption to occur, while the latter is a lower-energy barrier for diffusion in the pore cavities. X-ray diffraction studies at various methanol and ethanol loadings showed that the host porous structures E and M underwent different scissoring motions, leading to an increase in unit cell volume with the space group remaining unchanged during adsorption. The results are discussed in terms of reversible adsorbate/adsorbent (host/guest) structural changes and the adsorption mechanism involving hydrogen-bonding interactions with specific surface sites for methanol and ethanol adsorption in relation to pore size and extent of filling. This paper contains the first evidence for individual kinetic barriers to diffusion through windows and pore cavities in flexible porous coordination polymer frameworks.
LanguageEnglish
Pages9750-9759
Number of pages9
JournalJournal of the American Chemical Society
Volume126
Issue number31
DOIs
Publication statusPublished - Aug 2004

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Adsorption
Methanol
Ethanol
Gases
Metals
Vapors
Kinetics
Adsorbents
Energy barriers
Adsorbates
4,4'-bipyridyl
Hydrogen Bonding
Cell Size
Thermodynamics
Carbon Dioxide
X-Ray Diffraction
Stoichiometry
Pore size
Sorption
Carbon dioxide

Keywords

  • adsorption
  • gases
  • vapors
  • metal-organic framework materials
  • methanol
  • ethanol
  • adsorption kinetics
  • chemical engineering

Cite this

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title = "Adsorption of gases and vapors on nanoporous Ni-2(4,4 '-bipyridine)(3)(NO3)(4) metal-organic framework materials templated with methanol and ethanol: Structural effects in adsorption kinetics",
abstract = "Desolvation of Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2CH(3)OH and Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2C(2)H(5)OH give flexible metal-organic porous structures M and E, respectively, which have the same stoichiometry, but subtly different structures. This study combines measurements of the thermodynamics and kinetics of carbon dioxide, methanol, and ethanol sorption on adsorbents M and E over a range of temperatures with adsorbent structural characterization at different adsorbate (guest) loadings. The adsorption kinetics for methanol and ethanol adsorption on porous structure E obey a linear driving force (LDF) mass transfer model for adsorption at low surface coverage. The corresponding adsorption kinetics for porous structure M follow a double exponential (DE) model, which is consistent with two different barriers for diffusion through the windows and along the pores in the structure. The former is a high-energy barrier due to the opening of the windows in the structure, required to allow adsorption to occur, while the latter is a lower-energy barrier for diffusion in the pore cavities. X-ray diffraction studies at various methanol and ethanol loadings showed that the host porous structures E and M underwent different scissoring motions, leading to an increase in unit cell volume with the space group remaining unchanged during adsorption. The results are discussed in terms of reversible adsorbate/adsorbent (host/guest) structural changes and the adsorption mechanism involving hydrogen-bonding interactions with specific surface sites for methanol and ethanol adsorption in relation to pore size and extent of filling. This paper contains the first evidence for individual kinetic barriers to diffusion through windows and pore cavities in flexible porous coordination polymer frameworks.",
keywords = "adsorption, gases, vapors, metal-organic framework materials, methanol, ethanol, adsorption kinetics, chemical engineering",
author = "A.J. Fletcher and E.J. Cussen and D. Bradshaw and M.J. Rosseinsky and K.M. Thomas",
year = "2004",
month = "8",
doi = "10.1021/ja0490267",
language = "English",
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pages = "9750--9759",
journal = "Journal of the American Chemical Society",
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TY - JOUR

T1 - Adsorption of gases and vapors on nanoporous Ni-2(4,4 '-bipyridine)(3)(NO3)(4) metal-organic framework materials templated with methanol and ethanol: Structural effects in adsorption kinetics

AU - Fletcher, A.J.

AU - Cussen, E.J.

AU - Bradshaw, D.

AU - Rosseinsky, M.J.

AU - Thomas, K.M.

PY - 2004/8

Y1 - 2004/8

N2 - Desolvation of Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2CH(3)OH and Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2C(2)H(5)OH give flexible metal-organic porous structures M and E, respectively, which have the same stoichiometry, but subtly different structures. This study combines measurements of the thermodynamics and kinetics of carbon dioxide, methanol, and ethanol sorption on adsorbents M and E over a range of temperatures with adsorbent structural characterization at different adsorbate (guest) loadings. The adsorption kinetics for methanol and ethanol adsorption on porous structure E obey a linear driving force (LDF) mass transfer model for adsorption at low surface coverage. The corresponding adsorption kinetics for porous structure M follow a double exponential (DE) model, which is consistent with two different barriers for diffusion through the windows and along the pores in the structure. The former is a high-energy barrier due to the opening of the windows in the structure, required to allow adsorption to occur, while the latter is a lower-energy barrier for diffusion in the pore cavities. X-ray diffraction studies at various methanol and ethanol loadings showed that the host porous structures E and M underwent different scissoring motions, leading to an increase in unit cell volume with the space group remaining unchanged during adsorption. The results are discussed in terms of reversible adsorbate/adsorbent (host/guest) structural changes and the adsorption mechanism involving hydrogen-bonding interactions with specific surface sites for methanol and ethanol adsorption in relation to pore size and extent of filling. This paper contains the first evidence for individual kinetic barriers to diffusion through windows and pore cavities in flexible porous coordination polymer frameworks.

AB - Desolvation of Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2CH(3)OH and Ni(2)(4,4'-bipyridine)(3)(NO(3))(4).2C(2)H(5)OH give flexible metal-organic porous structures M and E, respectively, which have the same stoichiometry, but subtly different structures. This study combines measurements of the thermodynamics and kinetics of carbon dioxide, methanol, and ethanol sorption on adsorbents M and E over a range of temperatures with adsorbent structural characterization at different adsorbate (guest) loadings. The adsorption kinetics for methanol and ethanol adsorption on porous structure E obey a linear driving force (LDF) mass transfer model for adsorption at low surface coverage. The corresponding adsorption kinetics for porous structure M follow a double exponential (DE) model, which is consistent with two different barriers for diffusion through the windows and along the pores in the structure. The former is a high-energy barrier due to the opening of the windows in the structure, required to allow adsorption to occur, while the latter is a lower-energy barrier for diffusion in the pore cavities. X-ray diffraction studies at various methanol and ethanol loadings showed that the host porous structures E and M underwent different scissoring motions, leading to an increase in unit cell volume with the space group remaining unchanged during adsorption. The results are discussed in terms of reversible adsorbate/adsorbent (host/guest) structural changes and the adsorption mechanism involving hydrogen-bonding interactions with specific surface sites for methanol and ethanol adsorption in relation to pore size and extent of filling. This paper contains the first evidence for individual kinetic barriers to diffusion through windows and pore cavities in flexible porous coordination polymer frameworks.

KW - adsorption

KW - gases

KW - vapors

KW - metal-organic framework materials

KW - methanol

KW - ethanol

KW - adsorption kinetics

KW - chemical engineering

UR - http://dx.doi.org/10.1021/ja0490267

U2 - 10.1021/ja0490267

DO - 10.1021/ja0490267

M3 - Article

VL - 126

SP - 9750

EP - 9759

JO - Journal of the American Chemical Society

T2 - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 31

ER -