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

Abstract

The development of heterogeneous catalysts for promoting epoxide cycloaddition with carbon dioxide is highly desirable for recycling CO2 and achieving the goal of carbon neutrality. Herein, we designed and synthesized...

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

“…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. As shown in Scheme 2, the substrate of the epoxide is adsorbed and polarized by the Lewis acidic sites of the trinuclear Cr clusters in MIL-101-IL(BuBr).…”

“…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. As shown in Scheme 2, the substrate of the epoxide is adsorbed and polarized by the Lewis acidic sites of the trinuclear Cr clusters in MIL-101-IL(BuBr).…”

“…42 However, MIL-101-PTP exhibited catalytic activity with a CPC yield of 34% under the same conditions (Table 1, entry 2), owing to the enhanced adsorption for CO 2 and Lewis basicity afforded by the polypyridyl groups from the auxiliary ligand of PTP. 43,44 Compared with MIL-101-PTP, MIL-101-IL(RBr) (R = Et, Pr, Bu, and Pe) containing ionic liquids presented improved activity in the catalytic reaction of ECH cycloaddition (Table 1, entries 3-6), on account of the nucleophilicity from bromide anions of ILs. Generally, the CPC yield increased with the longer alkane chain of ILs in MIL-101-IL.…”

Nanocage-Based Tb3+-Organic Framework for Efficiently Catalyzing the Cycloaddition Reaction of CO2 with Epoxides and Knoevenagel Condensation

“…Furthermore, the results were consistent with previous literature reports: electron-withdrawing groups (−F, −CF 3 , −Cl, −CC) had a positive effect on the reaction (entries 2–4 and 6). − The molecular sizes of all epoxy derivatives are shown in Table S5. In addition, compared with various newly reported nanochannel-based MOF catalysts such as UiO-66-Gua0.2(s), 2, and Rh-PMOF-1 (Table ), − NUC-58a owns a more efficient catalytic activity, which should be due to the satisfactory structural merits from nanoporous channels, enough Lewis acidic sites from {Tb 4 } clusters, plentiful basic sites of N pyridine atoms, and μ 2 –OH groups.…”

A novel zirconium-based metal–organic framework covalently modified by methyl pyridinium bromide for mild and co-catalyst free conversion of CO2 to cyclic carbonates

“…Based on the above results, discussion of the experiment and previous literature studies, the plausible mechanism for the CO 2 cycloaddition reaction can be proposed. 40–43 As shown in Fig. 7, the ring-opening process can be facilitated by the Lewis acidic sites on the Zr 6 O 4 (OH) 4 cluster by forming an oxygen–metal intermediate.…”