Dry-Gel Conversion Synthesis of Zr-Based Metal–Organic Frameworks

Abstract

UiO-66 was successfully synthesized in the absence of any amide solvents and hydrochloric acid by using the dry-gel conversion (DGC) method for the first time. The prepared UiO-66 samples (denoted as UiO-66-DGC) were characterized by XRD, SEM, TGA, CO2 adsorption, NH3-TPD, and N2 adsorption. The results showed that the UiO-66-DGC-E sample synthesized by using ethanol as solvent has similar crystallinity and morphology to the UiO-66 sample prepared by the conventional solvothermal method (denoted as UiO-66-S). However, it has more linker deficiencies, indicating the presence of more defects exposed in Zr clusters. As a result, the prepared UiO-66-DGC-E sample exhibited high catalytic activity and reusability in esterification. This preparation method provides a new alternative method for the efficient and eco-friendly synthesis of metal–organic frameworks (MOFs) and modification of their properties.

Amino Acid Imprinted UiO-66s for Highly Recognized Adsorption of Small Angiotensin-Converting-Enzyme-Inhibitory Peptides

“…On the contrary, NH 3 -TPD curves in Figure 3d shows that the two successive peaks were shifted to lower temperatures, suggesting a decrease in surface acidity. 59,60 These results echoed each well with other. In light of 1 H NMR and XPS analysis, exposure of free-coordinated NH 2 -groups intensified surface alkalinity of UiO-66-W and UiO-66-F, while the former being equipped with more basic groups endowed higher surface alkalinity than the latter.…”

“…The two peaks in CO 2 -TPD curves in Figure c indicated a weak basic and a strong basic site respectively on UiO-66s. , Both of the peaks were shifted to higher temperatures upon the anchoring of Phe and Trp into UiO-66, indicating an increase in surface basicity. On the contrary, NH 3 -TPD curves in Figure d shows that the two successive peaks were shifted to lower temperatures, suggesting a decrease in surface acidity. , These results echoed each well with other. In light of 1 H NMR and XPS analysis, exposure of free-coordinated NH 2 - groups intensified surface alkalinity of UiO-66-W and UiO-66-F, while the former being equipped with more basic groups endowed higher surface alkalinity than the latter.…”

A Showcase of Green Chemistry: Sustainable Synthetic Approach of Zirconium‐Based MOF Materials

“…It is worth noting that the solvent can be reused to synthesis for several times, even though the textural properties and yield of Zr−MOFs in each cycle varied but still were in an acceptable range [103] . Lu et al [70f] . synthesized UiO‐66 by dry‐gel conversion without using high boiling point organic or acidic corrosive solvents, but ethanol, proving this method relatively efficient, eco‐friendly, and safe for green synthesis of Zr−MOFs, especially in lab scale.…”

Different Benzendicarboxylate-Directed Structural Variations and Properties of Four New Porous Cd(II)-Pyridyl-Triazole Coordination Polymers

“…Generally, the coordination preference of the nature of ligands and geometries of ions are the primary considerations in the preparation process of CPs. However, other factors, such as the choice of auxiliary ligands, pH, template effect, as well as reaction temperature, etc., are considered to be the great roles in the fabrications of the desired structures (Chen et al, 2015 ; Song et al, 2015 ; Waller et al, 2015 ; Blandez et al, 2016 ; Lannoeye et al, 2016 ; Manna et al, 2016 ; Rosa et al, 2016 ; Lu et al, 2017 ). Besides, the typical non-covalent supramolecular interlocks, including H-bonding, π···π stacking, etc., may also help to fine-tune the structural assemblies (Wheeler, 2013 ; Yadav and Gorbitz, 2013 ; Bhattacharya et al, 2014 , 2016 ; DeFuria et al, 2016 ; Ju et al, 2016 ; Li et al, 2016 , 2017 ; Song et al, 2016 ; Yao et al, 2016 ; Park et al, 2017 ).…”