Rapid, Microwave-Assisted Synthesis of Cubic, Three-Dimensional, Highly Porous MOF-205 for Room Temperature CO₂ Fixation via Cyclic Carbonate Synthesis

Abstract

A dual-porous, three-dimensional, metal-organic framework [ZnO(2,6-NDC)(BTB)] (MOF-205, BET = 4200 m/g) has been synthesized using microwave power as an alternative energy source for the first time, and its catalytic activity has been exploited for CO-epoxide coupling reactions to produce five-membered cyclic carbonates under solvent-free conditions. Microwave synthesis was performed at different time intervals to reveal the formation of the crystals. Significant conversion of various epoxides was obtained at room temperature, with excellent selectivity toward the desired five-membered cyclic carbonates. The importance of the dual porosity and the synergistic effect of quaternary ammonium salts on efficiently catalyzed CO conversion were investigated using various experimental and physicochemical characterization techniques, and the results were compared with those of the solvothermally synthesized MOF-205 sample. On the basis of literature and experimental inferences, a rationalized mechanism mediated by the zinc center of MOF-205 for the CO-epoxide cycloaddition reaction has been proposed.

Efficient Solvent‐Free Carbon Dioxide Fixation Reactions with Epoxides Under Mild Conditions by Mixed‐Ligand Zinc(II) Metal–Organic Frameworks

“…From structural data and previous studies, a probable synergistic mechanism during the catalysis by the ZnMOF‐1 /TBAB binary system is proposed, which is also relevant in the case of ZnMOF‐2 . The crystal structures of both ZnMOFs revealed N 2 O 4 coordination around the metal center; the carboxylate group chelated to the metal with a long Zn−O distance (Zn−O2=2.412 Å in ZnMOF‐1 and 2.356 Å in ZnMOF‐2 ) is susceptible for initial catalytic reaction.…”

Porous MOF‐205 with multiple modifications for efficiently storing hydrogen and methane as well as separating carbon dioxide from hydrogen and methane

“…MOF‐205, with chemical formula Zn 4 O(BTB) 4/3 (NDC) (BTB = benzene‐1,3,5‐benzoate; NDC = naphthalene‐2,6‐dicarboxylate), is a typical porous material with large surface area, free volume, and low density. These characteristics are all beneficial for gas adsorption.…”

“…54 Sun et al found that the adsorption affinity between a H 2 molecule with Li-doped heterofullerene C 48 B 12 55 (Li-C 48 B 12 ) is larger than Li-doped fullerene (Li-C 60 ), where each Li atom can bind up to three H 2 molecules leading to a gravimetric uptake of 9 wt%. 56 MOF-205, 57 with chemical formula Zn 4 O(BTB) 4/ 3 (NDC) (BTB = benzene-1,3,5-benzoate; NDC = naphthalene-2,6-dicarboxylate), is a typical porous material with large surface area, free volume, and low density. These characteristics are all beneficial for gas adsorption.…”

Sustainable Heterogeneous Catalysts for CO2 Utilization by Using Dual Ligand ZnII/CdII Metal–Organic Frameworks

“…However,alimited number of MOFs are known for efficient conversion of CO 2 under ambient reaction conditions such as atmospheric pressure, low loading of catalyst/co-catalyst, and room temperature. [78][79][80][81][82][83][84][85][86][87][88][89] On the basis of the above discussions and in ac ontinuation of our ongoing research activity, [12,90] we herewith presentt wo MOFs, {[M(CHDC)(L)]·H 2 O} n comprising Zn II (1)o rC d II (2)m etal nodes andb ipyridyl-based Schiff base ligand, 4-pyridyl carboxaldehyde isonicotinoylhydrazone (L)i nc ombination with flexible 1,4-cyclohexanedicarboxylic acid (H 2 CHDC) and their application in the area of heterogeneousc atalysis. Crystals of MOFs 1 and 2 wereh arvested by diffusion of precursor solutions and, alternatively,b oth MOFs can be obtained quantitatively by conventional reflux and mechanochemical reactionw here the metal salts and ligand precursors are ground together manually to produce bulk homogeneousp hase pure material.…”