Facile in Situ Halogen Functionalization via Triple-Bond Hydrohalogenation: Enhancing Sorption Capacities through Halogenation to Halofumarate-Based Zr(IV)-Metal-Organic Frameworks

Abstract

Surface halogenation is an important means to tune or improve functionalities of solid-state materials. However, this concept has been hardly explored and exploited in the engineering of metal-organic frameworks (MOFs). Here, a facile approach to obtain halo-functionalized derivatives of zirconium fumarate (MOF-801) is developed by reacting zirconium halides (ZrX4; X = Cl, Br, I) in water with acetylenedicarboxylic acid. The latter quantitatively undergoes an unusual in situ linker transformation into halofumarate via trans addition of HX to the −CC– triple bond. This HX addition and MOF formation happen in a one-pot reaction, that is, the in situ generated halogenated linker reacts with zirconium ions in solution to yield three microporous HHU-2-X MOFs (X = Cl, Br, I) with an fcu topology, containing UiO-type [Zr6O4(OH)4] secondary building units 12-fold connected by halofumarate linkers. The halogen (Cl) groups in HHU-2-Cl result in increased hydrophilicity for water vapor sorption as well as increased gas uptakes of 21% SO2, 24% CH4, 44% CO2, and 154% N2 when compared to the non-halogenated MOF-801. The tuning of the inner surface chemistry is realized to yield multipurpose adsorbent materials for enhanced gas and vapor uptakes over their non-halogenated analogues. The gas sorption properties of the chlorinated HHU-2-Cl material indicate its suitability for CO2, N2, and SO2 capture and separation, while its water sorption profile yields a high heat storage capacity of 500 kJ kg–1, making it promising for adsorption-based thermal batteries and dehumidification applications.

Chemical immobilization of amino acids into robust metal–organic framework for efficient SO2 removal

“…Some microporous anion‐pillared MOFs incorporated with polar inorganic anions (e.g., NbOF 5 2− and AlF 5 H 2 O 2− ) normally display steep adsorption at ultralow pressures and potentially indicate high energy penalties during regeneration 8 . Moreover, the similar acidic nature and kinetic diameter of SO 2 (4.11 Å) and CO 2 (3.30 Å) molecules are substantial challenges in preparing efficient and selective adsorbents 14 …”

Metal–Organic Frameworks Based on Group 3 and 4 Metals

“…[ 165 ] Moreover, a lot of similar Zr‐MOFs with fcu topology have been documented in past two years. [ 166–176 ] Linker elongation is one of the most important strategies to obtain MOFs with large pore sizes. However, fcu Zr‐MOFs tend to interpenetrate with increase of linker sizes.…”

“…[ 176 ] The halogen functionalized Zr‐HHU‐2‐Cl shows CO 2 capacity with an uptake amount up to 12.61 wt% at 293 K under 1 bar. [ 169 ] The interpenetrated Zr‐IAM‐4 also shows high CO 2 capacity with an uptake of 82.8, 57.9, and 35.4 cm 3 g −1 under 1 bar at 273, 283, and 298 K, respectively. [ 210 ] CO 2 adsorption properties of three imine‐based Zr‐MOFs, PCN‐161, PCN‐164, and DUT‐133, have also been investigated.…”

“…For example, CH 4 uptake amount of HHU‐2‐Cl is 16.08 cm 3 g −1 , which is higher than that of MOF‐801 at 293 K and 1 bar. [ 169 ] High‐pressure methane adsorption property of a Zr‐ZJU‐800 has also been studied under room temperature with a storage capacity of 10.0 mmol g −1 at 65 bar, which is 61.2% higher than that of the structural similar UiO‐66. [ 174 ]…”

“…Besides CO 2 and CH 4 , Zr‐MOFs can also be used for adsorption and storage of other gases. SO 2 adsorption properties of HHU‐2‐X and MOF‐801 were measured at 293 K. [ 169 ] Both isotherms are type I isotherms with large hysteresis loops. The SO 2 adsorption amount of HHU‐2‐Cl is a 21% higher than that of MOF‐801.…”