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Probing the Water Stability Limits and Degradation Pathways of Metal–Organic Frameworks
Author(s) -
Safy Mohamed E. A.,
Amin Muhamed,
Haikal Rana R.,
Elshazly Basma,
Wang Junjun,
Wang Yuemin,
Wöll Christof,
Alkordi Mohamed H.
Publication year - 2020
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202000207
Subject(s) - aqueous solution , metal organic framework , degradation (telecommunications) , chemistry , carboxylate , molecule , chemical stability , metal , in silico , hydroxide , stability (learning theory) , nanotechnology , biochemical engineering , materials science , computer science , inorganic chemistry , organic chemistry , telecommunications , biochemistry , adsorption , machine learning , engineering , gene
A comprehensive model to describe the water stability of prototypical metal–organic frameworks (MOFs) is derived by combining different types of theoretical and experimental approaches. The results provide an insight into the early stages of water‐triggered destabilization of MOFs and allow detailed pathways to be proposed for the degradation of different MOFs under aqueous conditions. The essential elements of the approach are computing the p K a values of coordinated water molecules and geometry relaxations. Variable‐temperature and pH infrared spectroscopy techniques are used to corroborate the main findings. The model developed herein helps to explain stability limits observed for several prototypical MOFs, including MOF‐5, HKUST‐1, UiO‐66, and MIL‐101‐Cr, in aqueous solutions, and thus, provides an insight into the possible degradation pathways in acidic and basic environments. The formation of a metal hydroxide through the autoprotolysis of metal‐coordinated water molecules and the strength of carboxylate–metal interactions are suggested to be two key players that govern stability in basic and acidic media, respectively. The methodology presented herein can effectively guide future efforts, which are especially significant for in silico screening, for developing novel MOFs with enhanced aqueous stability.