Ionic liquid accelerates the crystallization of Zr-based metal–organic frameworks

Abstract

The Zr-based metal–organic frameworks are generally prepared by solvothermal procedure. To overcome the slow kinetics of nucleation and crystallization of Zr-based metal–organic frameworks is of great interest and challenging. Here, we find that an ionic liquid as solvent can significantly accelerate the formation of Zr-based metal–organic frameworks at room temperature. For example, the reaction time is shortened to 0.5 h in 1-hexyl-3-methylimidazolium chloride for Zr-based metal–organic framework formation, while that in the conventional solvent N,N-dimethylformamide needs at least 120 h. The reaction mechanism was investigated in situ by 1H nuclear magnetic resonance, spectroscopy synchrotron small angle X-ray scattering and X-ray absorption fine structure. This rapid, low-energy, and facile route produces Zr-based metal–organic framework nanoparticles with small particle size, missing-linker defects and large surface area, which can be used as heterogeneous catalysts for Meerwein–Ponndorf–Verley reaction.

CO2 controls the oriented growth of metal-organic framework with highly accessible active sites

“…As catalyzed by Cu(BDC) synthesized at 3.40 and 6.40 MPa, the yields of benzaldehyde are 62% and 85%, respectively, while the yields of benzaldehyde catalyzed by Cu (BDC) synthesized at pressures higher than 7.38 MPa is 99% (Supplementary Table 2). It is obvious that the Cu(BDC) synthesized at higher pressure is more active, which can be attributed to its smaller size and more exposed active sites for catalysis 39 .…”

Facile and reversible digestion and regeneration of zirconium-based metal-organic frameworks

“…(3) generation of small-molecule products, particularly gases, can be beneficial to the digestion process due to larger entropy change. Furthermore, for the regeneration process, a probable mechanism is proposed according to the formation of UiO-66 [45][46][47] . After acid treatment and removal of CH 3 COONH 4 , NH 4 HCO 3 , and H 2 O by heat, the BDC and Zr(CH 3 COO) 4 are left.…”

A new post-synthetic polymerization strategy makes metal–organic frameworks more stable

“…Metal-organic frameworks (MOFs) have received tremendous attention due to unprecedented internal surface areas, tunable topologies, designable pore surfaces, [1][2][3][4][5][6][7] and their applicability in a number of energy related areas including catalysis, gas adsorption/separation, chemical sensing, energy storage/ conversion and so on. [8][9][10][11][12][13][14][15][16][17][18] However, weak coordination bonding can limit the stability of some MOFs in water, particularly at extreme pH. To overcome this instability issue and expand the practical applications of the existing MOFs, two main methods have recently been developed.…”