title: Combination of Optimization and Metalated-Ligand Exchange: An Effective Approach to Functionalize UiO-66(Zr) MOFs for CO2 Separation.
abstract: The strategy to functionalize water-stable metal-organic frameworks (MOFs) in order to improve their CO2 uptake capacities for efficient CO2 separation remains limited and challenging. We herein present an effective approach to functionalize a prominent water-stable MOF, UiO-66(Zr), by a combination of optimization and metalated-ligand exchange. In particular, by systematic optimization, we have successfully obtained UiO-66(Zr) of the highest BET surface area reported so far (1730 m(2)  g(-1) ). Moreover, it shows a hybrid Type I/IV N2 isotherm at 77 K and a mesopore size of 3.9 nm for the first time. The UiO-66 MOF underwent a metalated-ligand-exchange (MLE) process to yield a series of new UiO-66-type MOFs, among which UiO-66-(COONa)2 -EX and UiO-66-(COOLi)4 -EX MOFs have both enhanced CO2 working capacity and IAST CO2 /N2 selectivity. Our approach has thus suggested an alternative design to achieve water-stable MOFs with high crystallinity and gas uptake for efficient CO2 separation.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585 (Singapore).
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585 (Singapore).
authors.forename: Samuel
authors.initials: S
authors.lastname: Faucher
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585 (Singapore).
authors.forename: Yingying
authors.initials: Y
authors.lastname: Zhuo
authors.affiliation: Department of Mechanical Engineering, National University of Singapore, Singapore 117575 (Singapore).
authors.forename: Yao
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585 (Singapore).
authors.forename: Songnan
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117585 (Singapore). chezhao@nus.edu.sg.
authors.forename: Dan
authors.initials: D
authors.lastname: Zhao
keywords: UiO-66; adsorbents; mesoporous materials; metal-organic frameworks; metalated-ligand exchange