Zeolite-Like Metal Organic Framework (ZMOF) with a rho Topology for a CO₂ Cycloaddition to Epoxides

Abstract

The catalytic performances of two zeolite-like metal organic frameworks (rho-ZMOF and sod-ZMOF) were examined for the synthesis of chloropropene carbonate from CO2 and epichlorohydrin. rho-ZMOF exhibited superior catalytic activity compared to that of sod-ZMOF; rho-ZMOF achieved an excellent result of 98.0% conversion of epichlorohydrin with a 98.6% selectivity to the cyclic carbonate with tetrabutylammonium bromide as a cocatalyst after a 3 h reaction at 40 °C and 10 bar. rho-ZMOF retained good catalytic performance for up to five recycling runs without a loss in catalytic activity, whereas sod-ZMOF showed structural collapse during the recycling runs, which was similar to many other reported metal organic frameworks, such as ZIF-8. The high stability of rho-ZMOF for the liquid phase cycloaddition reaction was noteworthy and was believed to be derived from its more robust metal–ligand bonding in which the metal sites were coordinated by four bidentate ligands, rather than just the two found in sod-ZMOF with a coordination number of six.

Facile One-Pot Synthesis of Zn/Mg-MOF-74 with Unsaturated Coordination Metal Centers for Efficient CO2 Adsorption and Conversion to Cyclic Carbonates

“…4 The two strong peaks at 1568 and 1410 cm −1 were attributed to vibrations and asymmetric stretching of CO in the H 4 dhta. 34,35 The wavenumber of 1568 cm −1 in MOF-74 was lower than the normal wavenumber of CO because the benzene ring bonded to the benzene ring by CO to form a conjugate system and the electron cloud density in the system was averaged, resulting in the absorption frequency that moved to a lower wavenumber direction. The single peak at 1241 cm −1 was assigned to the C−O of H 4 dhta, demonstrating the organic ligand coordinated in the MOF-74.…”

Integration of polypyridyl-based ionic liquids into MIL-101 for promoting CO2 conversion into cyclic carbonates under cocatalyst-free and solventless conditions

“…43 With regard to epoxypropyl phenyl ether, the yield was just 26% (Table 2, entry 5), which could be attributed to the hindered interaction between the catalytic site and substrate because the epoxide with comparatively large molecular size could not be efficiently transported into the MOF pore. 48 It should be noted that MIL-101-IL(BuBr) could outperform the majority of the previously reported MOF-derived catalysts for epoxide cycloaddition with CO 2 under similar conditions (Table 3). 31,39,42,43,49,50 Based on the results of the aforementioned experiments and previous studies, 44,51,52 a putative mechanism for the epoxide-CO 2 cycloaddition catalyzed by MIL-101-IL(BuBr) is proposed.…”

Guanidyl-implanted UiO-66 as an efficient catalyst for the enhanced conversion of carbon dioxide into cyclic carbonates

“…The low conversion could be explained by the steric hindrance of the relatively large epoxide which would prevent the mass transfer of the substrate in the porous structures of the MOF. 42,43 Thus, the UiO-66-Gua 0.2 ( s ) catalyst has admirable size selectivity, and the cycloaddition reaction occurs in the frame cavity rather than on the surface of the frame. It was noted that UiO-66-Gua 0.2 ( s ) could surpass most of the MOF-based catalysts for the ECH and PO cycloaddition under mild pressure (Table S1†).…”