Tethering Dual Hydroxyls into Mesoporous Poly(ionic liquid)s for Chemical Fixation of CO₂ at Ambient Conditions: A Combined Experimental and Theoretical Study

Abstract

Vicinal dual hydroxyl functional mesoporous poly(ionic liquid)s with large surface area and high ionic liquid (IL) content were synthesized through the copolymerization of epoxy-containing IL monomers and divinylbenzene, followed by ring opening in water. They acted as recyclable heterogeneous organocatalysts in the cycloaddition of a series of epoxides with CO 2 under mild conditions (down to ambient conditions). The catalyst can be lightly recovered and reused with stable activity. The remarkable performance was attributable to the abundant mesoporosity and the synergistic effect of vicinal dual hydroxyls as hydrogen-bonding donors and halogen anions as nucleophiles. Density functional theory calculation, comprising the structural optimization, the energetic profile, and the charge and energy decomposition analysis by the combination of the extended transition state energy decomposition scheme with the natural orbitals for chemical valence approach, was performed to afford insight, indicating that the vicinal dual hydroxyls accelerated the reaction by providing a strong hydrogen-bonding effect and enhancing the leaving ability of the halogen anions.

Imidazolium‐Functionalized Ionic Hypercrosslinked Porous Polymers for Efficient Synthesis of Cyclic Carbonates from Simulated Flue Gas

“…In the case of similar chemical compositions, the porosity plays a vital role in the catalytic coupling of epoxide with CO 2 , especially diluted CO 2 . Normally, the larger surface area promotes the dispersion and accessibility of the active sites, and the abundant microporosity will significantly enrich the surface CO 2 to accelerate the conversion because the cycloaddition reaction rate is closely related to the CO 2 pressure (Figure a).…”

Assessing the pKa‐Dependent Activity of Hydroxyl Hydrogen Bond Donors in the Organocatalyzed Cycloaddition of Carbon Dioxide to Epoxides: Experimental and Theoretical Study

“…[7c] Neverthe-less, given several advantageous aspects of organocatalysis in terms of costs and sustainability, [1] the development of more active organocatalytic systems for the conversion of CO 2 to cyclic carbonates is highly sought after. [7e-g] Among them, hydroxyl HBDs are likely to represent the broadest family of catalytically active species and include functionalized monoalcohols, [20] glycols, [21] polyalcohols, [22] fluorinated alcohols, [23] hydroxy-functionalized N-heterocycles, [24] silanediols, [25] boronic acids, [26] carboxylic acids, [27] ascorbic acid [5] and several compounds containing phenolic [28] or polyhydroxyphenolic moieties. [5,19] Active HBDs for the cycloaddition of CO 2 to epoxides include several classes of compounds that have been careful reviewed.…”

Ultra‐small and highly dispersed Pd nanoparticles inside the pores of ZIF‐8: Sustainable approach to waste‐minimized Mizoroki–Heck cross‐coupling reaction based on reusable heterogeneous catalyst

“…Thus, in the design and synthesis of heterogeneous catalysts, various porous materials including mesoporous silicates, covalent organic frameworks, mesoporous organic polymers and especially metal–organic frameworks (MOFs) have been widely used as heterogeneous catalyst supports. Among the various matrixes, porous MOFs have attracted tremendous academic and industrial interest in the last few decades due to the extraordinary combination of features including well‐defined porosities, tunable crystalline structure, high surface area and chemical tenability .…”