Exceptionally Stable and 20-Connected Lanthanide Metal–Organic Frameworks for Selective CO₂ Capture and Conversion at Atmospheric Pressure

Abstract

Highly thermal and chemically stable, 20-connected lanthanide metal–organic frameworks (MOFs) [{Ln­(BTB)­(H2O)}­·H2O] n (where Ln = Sm (MOF1)/Gd (MOF2), BTB = 1,3,5-tris (4-carboxy phenyl) benzene) have been synthesized solvothermally and characterized by single-crystal X-ray diffraction analysis and other physicochemical methods. MOF1 and 2 are isostructural and feature three-dimensional honeycomb-like structure with large one-dimensional hexagonal channels of dimension ∼10.20 × 10.11 Å2. Gas uptake studies of the samples revealed selective adsorption properties of MOF1 for CO2 over other (N2, Ar, and H2) gases. The activated samples of the MOF1/2 act as efficient recyclable catalysts for heterogeneous cycloaddition of CO2 with styrene oxide, resulting in cyclic carbonate with high yield and selectivity. Interestingly, the pore size-dependent catalytic conversion of epoxides has been observed, suggesting the potential utility of MOF1 as a promising heterogeneous catalyst for cycloaddition of carbon dioxide. Furthermore, the MOF1 catalyst can be easily recycled for several cycles without significant loss of catalytic activity as well as structural rigidity. MOF1 and 2 represent rare examples of 20-c lanthanide MOFs exhibiting selective capture and efficient cycloaddition of CO2 with epoxides at mild conditions.

Cyclometalation of lanthanum(iii) based MOF for catalytic hydrogenation of carbon dioxide to formate

“…44 This was attributed to the framework exibility although other mechanisms were not ruled out. At 195 K, the amount of CO 2 uptake increases abruptly at low pressure range, with volumetric uptake more than doubling to 36.25 and 32.62 cm 3 40,[45][46][47] Catalysis NMR analysis of the digested MOFs before was carried out to conrm that no DMF molecules in the MOF catalysts and the formate product observed in our reaction was not from the DMF molecules. The conversion of CO 2 to formate using JMS-1a and Ru(II) @JMS-1a as catalysts was carried out as described in the experimental section.…”

“…However, we are aware of the catalytic activities of lanthanides metals reported in literature. 45,49 Having this in mind, we soaked our reactors in acid for 24 h and repeated the experiments several times using JMS-1a as the solid catalyst. These repeated experiments gave formate as the catalytic product, this conrmed that the La(III) MOF act as a catalyst for reduction of CO 2 .…”

Synthesis and Characterization of 2D Metal-Organic Frameworks for Adsorption of Carbon Dioxide and Hydrogen

“…Upon activation, the PXRD pattern of JMS-3a (Figure 3) shows that structural transformation is not much as compared to JMS-4a (Figure 7). The adsorption branches of the isotherm carried out at 273 and 298 K were used to obtain a precise prediction over the quantity of CO 2 adsorbed at the saturation point (Ugale et al, 2018). The estimated values of isosteric heat (Q st ) of adsorption for JMS-3a were found to be 33-34 kJ mol −1 at loading values ranging from 0.12 to 0.99 mmol g −1 (Supplementary Figure 4).…”

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

“…[11][12][13][14][15][16] Cycloadditiono fC O 2 to epoxidesf or generation of cyclic carbonates by as uitable catalytic materialisone of the mostpromising methods for utilization of CO 2 to give value-added products. [17][18][19][20][21][22][23][24] Cyclic carbonates offer widespread applications as raw materials in fine chemical, cosmetics, intermediates in the synthesis of ethylene glycol, acyclic carbonates, polymers,a ss olvents, and as electrolytes in batteries. [25][26][27][28][29][30][31][32][33] For catalytic cycloaddition of CO 2 with epoxides to generate cyclic carbonates, av ariety of homogeneousc atalysts such as transition-metal complexes,i onic liquids, organocatalysts, and quaternary ammoniumo rp hosphonium salts, etc.,h ave been extensively studied, but catalyst recycling and product separation issues limit their practicality.…”

“…Hence, development of new catalytic materials for the selective capture and conversion of CO 2 into useful chemicals at ambient conditions has gained significant importance . Cycloaddition of CO 2 to epoxides for generation of cyclic carbonates by a suitable catalytic material is one of the most promising methods for utilization of CO 2 to give value‐added products . Cyclic carbonates offer widespread applications as raw materials in fine chemical, cosmetics, intermediates in the synthesis of ethylene glycol, acyclic carbonates, polymers, as solvents, and as electrolytes in batteries …”