Facile Approach to Graft Ionic Liquid into MOF for Improving the Efficiency of CO₂ Chemical Fixation

Abstract

This work describes a facile approach to modify metal-organic frameworks (MOFs) with ionic liquids (ILs), rendering them as useful heterogeneous catalysts for CO chemical fixation. An amino-functionalized imidazolium-based ionic liquid is firmly grafted into the porous MOF, MIL-101-SOH by the acid-base attraction between positively charged ammonium groups on the IL and negatively charged sulfonate groups from the MOF. Analyses by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, H NMR, and N sorption experiments reveal the MOF-supported ionic liquid (denoted as IL@MOF) material remains intact while functioning as a recyclable heterogeneous catalyst that can efficiently convert CO and epichlorohydrin into chloropropene carbonate without the addition of a cocatalyst.

Metal‐Organic Frameworks as Platform for Lewis‐Acid‐Catalyzed Organic Transformations

“…demonstrated use of ionic liquid supported MOFs for cyclization of CO 2 with epichlorohydrin wherein the reaction was performed under atmospheric pressure. Importantly, the reaction does not require the addition of co‐catalyst Bu 4 NBr . Significant enhancement of product formation was obtained when IL@MIL‐101‐SO 3 H ( 48 ) was used compared to MIL‐101‐SO 3 Na with a very nominal loading, 0.4167 to 0.5820 mmol g −1 .…”

“…The catalytic reactions give yield up to 90 %. Another Ti based MOF NH 2 ‐MIL‐125, which works well under solvent free conditions is Ti 8 O 8 (OH) 4 (bdc‐NH 2 ) 6 ( 50 ) . These examples are very important in view of economic and environment viability.…”

Ionic Polyureas—A Novel Subclass of Poly(Ionic Liquid)s for CO2 Capture

“…Over the past 10 years, various sorbents derived from both linear [ 4 , 17 , 18 , 19 ] and cross-linked [ 20 , 21 , 22 ] PILs have been investigated (see the examples in Scheme 1 and in Table 2). To enhance PILs’ CO 2 sorption capacity, a number of approaches have been applied, such as PILs’ immobilization on carbon fibers [ 23 , 24 ], grafting of PILs on silica nanoparticles [ 25 , 26 , 27 ], incorporation of PILs into a metal–organic framework (MOF) [ 28 , 29 , 30 , 31 ] or preparation of ordered porous PIL-based crystallines [ 32 ]. It was found that the CO 2 adsorption behavior of PILs is dependent on many factors, such as their chemical composition (nature of the cation and anion, type of the polymer backbone), molar mass and pore structure (surface area, pore size, atomic packing, etc.)…”

Rational Construction of an Exceptionally Stable MOF Catalyst with Metal‐Adeninate Vertices toward CO2 Cycloaddition under Mild and Cocatalyst‐Free Conditions

“…However, cocatalysts are required in most cases, which results in extra waste and environmental pollution . To date, some strategies have been explored for the introduction of cocatalyst into MOFs by guest capture, postmodified skeleton and functionalization of organic ligands . For example, a flexible ionic polymer can be inserted into a MOF host, which will efficiently fixate CO 2 with epoxides to afford cyclic carbonates under mild and cocatalyst‐free conditions .…”

“…[31][32][33][34] To date, some strategies have been explored for the introduction of cocatalyst into MOFs by guest capture, postmodified skeleton and functionalization of organic ligands. [35][36][37][38][39][40] For example,aflexible ionic polymer can be inserted into aM OF host, which will efficientlyf ixate CO 2 with epoxides to afford cyclic carbonates under mild and cocatalyst-free conditions. [41] Our recent work has presented the encapsulationo fa ni onic metalloporphyrin into ZIF-8 in situ for solvent-free synthesis of cyclic carbonates from CO 2 and epoxides withouta ny cocatalyst under 1atm CO 2 .H owever, multistep synthesisa nd processing are required in these cases, as well as low loading amountso ff unctional components.…”