Ying-Hua Zhou

Metal-organic frameworks (MOFs) possess highly tunable structures, making them promising heterogeneous catalysts for efficient CO2 conversion reactions. In this work, cerium-modified zirconium-based metal-organic frameworks (ZrCe-UiO-66) were engineered and post-synthetically functionalized with dicationic ionic liquid moieties, enabling the simultaneous introduction of strong Lewis acidic sites and nucleophilic ionic liquid units without the need for external cocatalysts. The resulting ZrCe0.5-UiO-66-DIL(n-PyRIm) ( n = 2, 3, 4; R = Et, Pr, Bu, Pe) MOF hybrids were prepared via a modular grafting approach and exhibited remarkable catalytic performance. Among them, ZrCe0.5-UiO-66-DIL(2-PyBuIm) converted epichlorohydrin to the corresponding cyclic carbonate with 96% yield and 98% selectivity under solvent-free conditions at 110 °C and atmospheric CO2 pressure (0.1 MPa). This outstanding activity arises from a cooperative activation mechanism, in which the mixed Zr4+/Ce4+ metal nodes polarize the epoxide substrate, while the bromide anions embedded in the ionic liquid moieties promote nucleophilic ring opening. In addition to high catalytic efficiency, the MOF hybrids demonstrated excellent recyclability and broad substrate tolerance. Combined CO2 adsorption measurements and in situ infrared spectroscopy further revealed key surface intermediates, enabling a plausible mechanistic pathway for the cycloaddition process to be proposed.

CO₂ chemical fixation offers a feasible approach for carbon mitigation and high‐value utilization, but it is still challenging to develop an efficient catalyst for CO₂ conversion into cyclic carbonate. Herein, the triethylenediamine‐derived dicationic ionic liquids (DIL‐X, X = Cl, Br, and I) were grafted into UiO‐66 linkers through self‐assembly of Zr⁴⁺ ions and the mixed ligands of terephthalic acid and DIL‐bearing dicarboxylic acid, resulting in UiO‐66‐DIL‐X_n, (n designated as molar amount of the feeding DIL‐X). Their catalytic performance was evaluated by the epoxide cycloaddition reaction in the absence of solvent and cocatalyst. Among them, the UiO‐66‐DIL‐Cl_0.4 catalyst exhibited outstanding performance, with a chloropropene carbonate yield of 92% and a high selectivity of 99% under 0.1 MPa CO₂ at 110 °C for 16 h. Its high activity could be ascribed to the cooperativity among Lewis acidity of MOF nodes, the enhanced CO₂ absorption, and the strong nucleophilicity offered by halogen ions of ionic liquid‐modified MOF. Moreover, UiO‐66‐DIL‐Cl_0.4 presented excellent recyclability and substrate extension. A potential catalytic mechanism for the epoxide‐CO₂ cycloaddition into cyclic carbonate has been proposed. This work will shed light on the rational design of functionalized MOFs‐based catalysts for CO₂ utilization.

Pd-Doped Co nanoparticles were incorporated into Ti₃C₂/UiO-66-NH₂ composite. The heterogeneous catalyst exhibited outstanding catalytic activity for the dehydrogenation of ammonia borane under light irradiation at 298 K.

The polypyridyl-based ionic liquid-functionalized MIL-101(Cr) greatly enhanced the epoxide–CO ₂ cycloaddition reaction under cocatalyst-free and solventless conditions.

The guanidyl-modified UiO-66 exhibited great activity for epoxide-CO₂ cycloaddition with Bu₄NBr cocatalyst, attributed to the synergistic effect of guanidyl groups as hydrogen-bond donors and Zr centers as Lewis-acidic sites.