Details
| Original language | English |
|---|---|
| Article number | 110503 |
| Journal | Microporous and Mesoporous Materials |
| Volume | 309 |
| Early online date | 8 Aug 2020 |
| Publication status | Published - 15 Dec 2020 |
Abstract
The dehydration of the CPO-27-M (M-MOF-74, M = Zn, Co, Ni, Mg, Mn, Cu) metal-organic framework series has been investigated comprehensively using in situ variable temperature powder X-ray diffraction (VT-PXRD) and thermal analysis (TG) coupled with mass spectrometry (MS). Significant differences in the order of water desorption from different adsorption sites on heating are found with varying metal cation in the otherwise isostructural material. For all CPO-27-M (except M = Cu), water is bonded significantly more strongly to the accessible open metal sites, and these water molecules are only desorbed at higher temperatures than the other water molecules. CPO-27-Cu is an exception, where all water molecules desorb simultaneously and at much lower temperatures (below 340 K). MS and TG data show that all CPO-27-M start to release traces of CO2 already at 300–350 K, and thus long before bulk thermal decomposition is observed. Only for CPO-27-Co, the CO2 release is essentially constant on its baseline between 450 and 700 K, and it is the only CPO-27-M member that shows a stable plateau in the TG in this region. Additional rehydration studies on CPO-27-Co show that the MOF incorporates any water molecules present until the pores are fully loaded. CPO-27-Co consequently behaves as an efficient trap for any water present.
Keywords
- CPO-27-M, Dehydration, In situ techniques, M-MOF-74, Metal-organic frameworks, Phase transitions, Thermal analysis, X-ray diffraction
ASJC Scopus subject areas
- Chemistry(all)
- Materials Science(all)
- Physics and Astronomy(all)
- Condensed Matter Physics
- Engineering(all)
- Mechanics of Materials
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In: Microporous and Mesoporous Materials, Vol. 309, 110503, 15.12.2020.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Role of the metal cation in the dehydration of the microporous metal–organic frameworks CPO-27-M
AU - Rosnes, Mali H.
AU - Pato-Doldán, Breogán
AU - Johnsen, Rune E.
AU - Mundstock, Alexander
AU - Caro, Jürgen
AU - Dietzel, Pascal D.C.
N1 - Funding Information: The authors would like to thank Dr. Dmitry Chernyshov, Dr. Alexey Mikheykin, Dr. Vadim Diadkin, and Dr. Wouter van Beek at the Swiss–Norwegian Beamlines for their support in performing the experiments at the ESRF, and acknowledge the support from the Research Council of Norway through the FRINATEK Program (grant 221596 ), ISP-KJEMI Program (grant 209339 ) and SYNKNOYT (grants 227702 and 247734 ).
PY - 2020/12/15
Y1 - 2020/12/15
N2 - The dehydration of the CPO-27-M (M-MOF-74, M = Zn, Co, Ni, Mg, Mn, Cu) metal-organic framework series has been investigated comprehensively using in situ variable temperature powder X-ray diffraction (VT-PXRD) and thermal analysis (TG) coupled with mass spectrometry (MS). Significant differences in the order of water desorption from different adsorption sites on heating are found with varying metal cation in the otherwise isostructural material. For all CPO-27-M (except M = Cu), water is bonded significantly more strongly to the accessible open metal sites, and these water molecules are only desorbed at higher temperatures than the other water molecules. CPO-27-Cu is an exception, where all water molecules desorb simultaneously and at much lower temperatures (below 340 K). MS and TG data show that all CPO-27-M start to release traces of CO2 already at 300–350 K, and thus long before bulk thermal decomposition is observed. Only for CPO-27-Co, the CO2 release is essentially constant on its baseline between 450 and 700 K, and it is the only CPO-27-M member that shows a stable plateau in the TG in this region. Additional rehydration studies on CPO-27-Co show that the MOF incorporates any water molecules present until the pores are fully loaded. CPO-27-Co consequently behaves as an efficient trap for any water present.
AB - The dehydration of the CPO-27-M (M-MOF-74, M = Zn, Co, Ni, Mg, Mn, Cu) metal-organic framework series has been investigated comprehensively using in situ variable temperature powder X-ray diffraction (VT-PXRD) and thermal analysis (TG) coupled with mass spectrometry (MS). Significant differences in the order of water desorption from different adsorption sites on heating are found with varying metal cation in the otherwise isostructural material. For all CPO-27-M (except M = Cu), water is bonded significantly more strongly to the accessible open metal sites, and these water molecules are only desorbed at higher temperatures than the other water molecules. CPO-27-Cu is an exception, where all water molecules desorb simultaneously and at much lower temperatures (below 340 K). MS and TG data show that all CPO-27-M start to release traces of CO2 already at 300–350 K, and thus long before bulk thermal decomposition is observed. Only for CPO-27-Co, the CO2 release is essentially constant on its baseline between 450 and 700 K, and it is the only CPO-27-M member that shows a stable plateau in the TG in this region. Additional rehydration studies on CPO-27-Co show that the MOF incorporates any water molecules present until the pores are fully loaded. CPO-27-Co consequently behaves as an efficient trap for any water present.
KW - CPO-27-M
KW - Dehydration
KW - In situ techniques
KW - M-MOF-74
KW - Metal-organic frameworks
KW - Phase transitions
KW - Thermal analysis
KW - X-ray diffraction
UR - http://www.scopus.com/inward/record.url?scp=85090888800&partnerID=8YFLogxK
U2 - 10.1016/j.micromeso.2020.110503
DO - 10.1016/j.micromeso.2020.110503
M3 - Article
AN - SCOPUS:85090888800
VL - 309
JO - Microporous and Mesoporous Materials
JF - Microporous and Mesoporous Materials
SN - 1387-1811
M1 - 110503
ER -