Cycloaddition Of Carbon Dioxide Research Articles

Metal Organic Frameworks as Heterogeneous Catalysts in Olefin Epoxidation and Carbon Dioxide Cycloaddition

Metal–organic frameworks (MOFs) are a family of porous crystalline materials that serve in some cases as versatile platforms for catalysis. In this review, we overview the recent developments about the use of these species as heterogeneous catalysts in olefin epoxidation and carbon dioxide cycloaddition. We report the most important results obtained in this field relating them to the presence of specific organic linkers, metal nodes or clusters and mixed-metal species. Recent advances obtained with MOF nanocomposites were also described. Finally we compare the results and summarize the major insights in specific Tables, outlining the major challenges for this emerging field. This work could promote new research aimed at producing coordination polymers and MOFs able to catalyse a broader range of CO2 consuming reactions.

Experimental and theoretical investigation for the cycloaddition of carbon dioxide to epoxides catalyzed by potassium and boron co-doped carbon nitride

Much endeavor has been devoted to efficient heterogeneous catalysts for carbon dioxide (CO2) conversion to high-value chemicals. Meanwhile, the cycloaddition of CO2 to epoxides is considered as a green and atom-economy reaction to produce cyclic carbonates. Herein, a series of K, B co-doped CN with various doping contents (K, B-CN-X) were developed by simple one-step calcination of melamine and KBH4. B was confirmed to replace the C site and KN bond was formed, which was verified by XPS (X-ray photoelectron spectroscopy) and DFT (density functional theory) calculation. Particularly, K, B-CN-4 displayed the optimal catalytic performance in the presence of Bu4NBr (tetrabutylammonium bromide) cocatalyst for the CO2 cycloaddition with propylene oxide. Besides, K, B-CN-4/Bu4NBr catalyst exhibited good substrate versatility to various epoxides and excellent recycling performance. According to the DFT calculation on CO2 adsorption and experimental results, K, B-CN-4 presented satisfactory catalytic activity due to the enhanced CO2 adsorption after K and B dopings then the possible reaction mechanism was proposed. The promising K, B-CN-X catalyst presented an attractive application due to the simple, eco-friendly synthesis route for the efficient fixation of CO2.

Preparation of polyvinyl alcohol–chitosan–NH4Br catalyst and its application to cycloaddition of carbon dioxide to propylene oxide

AbstractAn eco‐friendly polyvinyl alcohol (PVA)–chitosan(CS)–NH4Br catalyst was prepared using a modified solution method. Although the amounts of PVA and CS were fixed, the amount of NH4Br was varied in the range 15–45 wt.%. The catalytic performance of PVA–CS–NH4Br was compared based on the carbonation performance in the presence of single‐component catalysts (PVA, CS, and NH4Br) and dual component catalyst (PVA–CS). The catalytic activity of PVA–CS was inadequate and considerably less than that observed when either PVA or CS was exclusively loaded. The number of functional groups within the PVA–CS structure was presumed to have been reduced due to the interactions of the OH groups in PVA and CS. However, the PVA–CS–NH4Br catalyst distinctively exhibited its catalytic performance. It has been suggested that NH4Br aided in sustaining the innate functional groups that both PVA and CS have within the PVA–CS–NH4Br structure. These results indicate that the functional groups and nucleophiles within the PVA–CS–NH4Br structure more effectively participated in the carbonation of propylene oxide. Quantitatively, the addition of 30 wt.% NH4Br yielded the best performance. Characteristic analyses of the catalysts were performed using X‐ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy.

Synergistic Catalysis of Ionic Liquid-Decorated Covalent Organic Frameworks with Polyoxometalates for CO2 Cycloaddition Reaction under Mild Conditions

The cycloaddition of carbon dioxide (CO2) with epoxides to yield highly value-added cyclic carbonates is an effective way to chemically utilize and convert CO2. Here, a heterogeneous catalyst of imidazole ionic liquid-decorated covalent organic framework with polyoxometalates (POM@ImTD-COF) was constructed by the covalent modification of ionic liquids to COFs and the electrostatic interaction between POMs and ionic liquids. The obtained POM@ImTD-COF shows high catalytic activity for CO2 cycloaddition reaction under mild conditions (1 atm and 80 °C) in the presence of a co-catalyst, and the catalytic activity of POM@ImTD-COF has no obvious decrease during reusing five times. The excellent catalytic performance is mainly attributed to the synergistic effect of ionic liquids, POMs, and COFs. In the cycloaddition process, ionic liquids and the co-catalyst weaken the C-O bond of epoxides and promote the ring opening of epoxides. POMs as the Lewis acids facilitate the insertion of CO2 to form reaction intermediates. The multiple activation effect of ionic liquids and POMs together with the CO2 adsorption effect and well-dispersed active sites in COFs contribute to the remarkable catalytic performance.

Cobalt-porphyrin modified graphene oxide as a heterogeneous catalyst for solvent-free CO2 fixation to cyclic carbonates

Chemical fixation of carbon dioxide into commodity chemicals is an appealing approach for CO2 transformations and utilizations. The challenge is to develop highly efficient and reusable heterogeneous catalysts. Herein, a cobalt-porphyrin modified graphene oxide (GOPCoCl) has been prepared with chemical functionalization by the acylation and amidation process on the graphene oxide support, and applied as a heterogeneous catalyst for the solvent-free cycloaddition of carbon dioxide and epoxides. The as-received GOPCoCl has been characterized by different methods, demonstrating that the metalloporphyrin is covalently linked to the graphene oxide (GO) surface. Owing to the uniform active sites and support effects, the catalyst behaved efficient catalytic performance, excellent recyclability, and good substrate expansibility for this solvent-free cycloaddition. Moreover, a synergetic catalytic mechanism has been prudently proposed based on the catalytic system and experimental results.

Highly Active Chromium Complexes Supported by Constrained Schiff-Base Ligands for Cycloaddition of Carbon Dioxide to Epoxides.

Novel constrained Schiff-base ligands (inden) were developed based on the well-known salen ligands. Chromium complexes supported by the constrained inden ligands were successfully synthesized and used as catalysts for the synthesis of cyclic carbonates from epoxides and carbon dioxide (CO2). The catalyst having tert-butyl (tBu) groups as substituents in combination with tetrabutylammonium bromide (TBAB) as a cocatalyst exhibited very high catalytic activity with a turnover frequency of up to 14800 h-1 for the conversion of CO2 and propylene oxide into propylene carbonate exclusively at 100 °C and 300 psi of CO2 under solvent-free conditions. The catalyst was found to be highly active for various epoxide substrates to produce terminal cyclic carbonates in 100% selectivity.

Dual-ionic imidazolium salts to promote synthesis of cyclic carbonates at atmospheric pressure

Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure (0.1 MPa) without any solvent and co-catalyst leading to 96.1% product yield. It can be reused five times to keep the product yield over 90%. These intriguing results are attributed to a new reaction mechanism, which is supported by theoretical calculations along with the measurements of 13C NMR spectrum and Fourier transform infrared spectroscopy (FT-IR). The excellent catalytic activity can be traced to a CO2-philic group along with an electrophilic hydrogen atom. Our work shows that incorporation of CO2-philic group is an feasible pathway to develop the new efficient ionic liquids.

Propylene Oxide Cycloaddition with Carbon Dioxide and Homopolymerization: Application of Commercial Beta Zeolites

The discovery of sustainable catalysts remains a key challenge in the advances of carbon dioxide utilization and polymer synthesis. Despite beta zeolites being widely used in industry as a kind of economical heterogeneous catalysts, their applications for carbon dioxide utilization and epoxides transformation remain relatively unexplored. Herein, we report the catalytic performance of commercial beta zeolites for the cycloaddition of carbon dioxide with epoxides as well as propylene oxide homopolymerization. The beta zeolites with different Si/Al ratios exhibit distinct properties in the reactions: (1) The one with high Si/Al ratio could catalyze the cycloaddition reaction with high selectivity to produce cyclic carbonate, and the reaction could be carried out even at ambient temperature and atmospheric pressure. Additionally, the zeolite is not sensitive to water or oxygen in the cycloaddition reaction, and it shows reusability with almost no change in activity. (2) The zeolite with low Si/Al ratio could catalyze the propylene oxide homopolymerization in the absence of CO₂ and a cocatalyst to produce polyether polyols. Interestingly, the polyether polyols obtained using this zeolite have similar molecular weights, irrespective of reaction conditions or conversion degrees of epoxide. The structural variety of the Si/Al ratio allows for switching the selectivity of zeolite in the reactions.

Cycloaddition of carbon dioxide and epoxides catalyzed by rare earth metal complexes bearing a Trost ligand

Rare earth metal complexes containing Trost ligands were used to catalyze the cycloaddition reaction of epoxides with CO2. A series of epoxides were successfully converted into the corresponding cyclic carbonates under mild conditions.

Nanoparticles of aromatic biopolymers catalyze CO2 cycloaddition to epoxides under atmospheric conditions

Nanoparticles from lignin and melanin derivatives are suitable sustainable catalysts for the cycloaddition of carbon dioxide to epoxides.

Cycloaddition of carbon dioxide to epoxides by highly active constrained aluminum chloride complexes.

The transformation of carbon dioxide (CO2) and epoxides to cyclic carbonates has gained much interest due to its low cost, abundance, low toxicity, and renewability. Therefore, novel constrained aluminum chloride complexes were developed based on bis(salicylimine) ligands for epoxides/CO2 coupling reactions. The five-membered rings attached to the aromatic rings were designed to enlarge the coordination pocket around the aluminum center as demonstrated by single-crystal X-ray crystallography. Addition of propylene oxide (PO) to a mixture of an aluminum chloride complex and tetrabutylammonium bromide (TBAB) rapidly gave (ligand)Al-OCH(Me)CH2Cl and (ligand)Al-OCH(Me)CH2Br in similar quantities. The anion exchange between (ligand)Al-Cl and TBAB was found to be faster than the ring-opening of PO. From a series of catalyst screening and optimization, the combination of catalyst 2g having no substituent on the aromatic rings and TBAB displayed very high activity (TOF up to 10 800 h-1) for the PO/CO2 coupling reaction. This catalyst system was extended to eleven more examples of epoxides. Moreover, excellent selectivity for cyclic carbonate production was observed for both terminal and internal epoxides.

Construction of Hybrid Bimetallic Uranyl Compounds Based on a Preassembled Terpyridine Metalloligand.

Six hybrid uranyl-transition metal compounds [UO2 Ni(cptpy)2 (HCOO)2 (DMF)(H2 O)] (1), [UO2 Ni(cptpy)2 (BTPA)2 ] (2), [UO2 Fe(cptpy)2 (HCOO)2 (DMF)(H2 O)] (3), [UO2 Fe(cptpy)2 (BTPA)2 ] (4), [UO2 Co(cptpy)2 (HCOO)2 (DMF)(H2 O)] (5), and [UO2 Co(cptpy)2 (BTPA)2 ] (6), based on bifunctional ligand 4'-(4-carboxyphenyl)-2,2':6',2''-terpyridine (Hcptpy) are reported (H2 BTPA = 4,4'-biphenyldicarboxylic acid). Single-crystal XRD revealed that all six compounds feature similar metalloligands, which consist of two cptpy- anions and one transition metal cation. The metalloligand M(cptpy)2 can be considered to be an extended linear dicarboxylic ligand with length of 22.12 Å. Compounds 1, 3, and 5 are isomers, and all of them feature 1D chain structures. The adjacent 1D chains are connected together by hydrogen bonds and π-π interactions to form a 3D porous structure, which is filled with solvent molecules and can be exchanged with I2 . Compounds 2, 4, and 6 are also isomers, and all of them feature 2D honeycomb (6,3) networks with hexagonal units of dimensions 41.91×26.89 Å, which are the largest among uranyl compounds with honeycomb networks. The large aperture allows two sets of equivalent networks to be entangled together to result in a 2D+2D→3D polycatenated framework. Remarkably, these uranyl compounds exhibit high catalytic activity for cycloaddition of carbon dioxide. Moreover, the geometric and electronic structures of compounds 1 and 2 are systematically discussed on the basis of DFT calculations.

Fixation of CO2 into Cyclic Carbonates by Halogen-Bonding Catalysis.

Halogen bonding, parallel to hydrogen bonding, was introduced into the catalytic cycloaddition of carbon dioxide into epoxide (CCE) reactions. A series of halogen-bond donor (XBD) catalysts of N-iodopyridinium halide featured with N-I bond were synthesized and evaluated in CCE reactions. The optimal XBD catalyst, 4-(dimethylamino)-N-iodopyridinium bromide ([DMAPI]Br), under screened conditions at 100 °C, ambient pressure, and 1 mol % catalyst loading, realized 93 % conversion of styrene oxide into cyclic carbonate in 6 h. The substrate scope was successfully extended with excellent yields (mostly ≥93 %) and quantitative selectivity (more than 99 %). 1 H NMR spectroscopy of the catalyst [DMAPI]Br on substrate epoxide certified that the N-I bond directly coordinated with the epoxide oxygen. A plausible mechanism of halogen-bonding catalysis was proposed, in which the DMAPI cation functioned as halogen-bond donor to activate the epoxide, and the counter anion bromide attacked the methylene carbon to initiate the ring-opening of the epoxide. CCE reactions promoted by N-iodopyridinium halide, exemplify a first case of halogen-bonding catalysis in epoxide activation and CO2 transformation.

The efficient catalytic microsystem with halogen-free catalyst for the intensification on CO2 cycloaddition

The cycloaddition of carbon dioxide in the traditional autoclave usually suffers from the factors including long reaction time and high pressure. An efficient catalytic microsystem (micro-reaction pools, MRPs) is developed for the microinterface intensification on the reaction. The MRPs can greatly accelerate the gas liquid catalytic reactions. Liquid containing reactant and halogen-free catalyst ([C1C6Im][HCO3]) were capsulated with silicon nanoparticles to form micron particles, which have prominent liquidity and considerable interface for the cycloaddition. CO2 can easily pass the porous thin shell composed of nano-silicon and reach the liquid core. Due to the greatly enlarged specific surface area, MRPs possess much better reaction performance than the traditional gas–liquid systems, as well as the excellent recyclability. The reaction rate is at least twice than that of the autoclave, which greatly reduces the reaction time. Accordingly, MRPs can effectively reduce the reaction temperature and pressure, which is beneficial to the energy saving and process safety.

Theoretical study on chemical fixation of carbon dioxide with aziridine into cyclic carbamate catalysed by purine/HI system

The cycloaddition of carbon dioxide with aziridine into cyclic carbamate catalysed by purine/HI has been investigated using exchange–correlation functional B3LYP of DFT and the 6-31+G(d,p) basis set for non-iodine atoms and the LANL2DZ for iodine in order to understand the catalytic efficiency of purine/HI system. Two hypothetical reaction mechanisms were proposed for the studied reaction in each catalyst systems. Thermodynamic and kinetic parameters were computed for each step to determine the more favourable route. The calculations reveal that the reaction prefers to proceed through a three-step mechanism in both purine and purine/HI catalyst system. HI plays a co-catalytic role to promote the initial ring-opening of aziridine. The obtained results emphasise purine/HI system had better catalytic efficiency than purine and mechanism II of purine/HI catalysed reaction is more favourable than mechanism I. The more favourable pathway comprises three steps such as ring-opening of aziridine by iodine anion, CO2 insertion and ring-closure. The CO2 insertion step was determined as barrierless. The ring-opening of aziridine was rate-determining step which requires 16.79, 16.33, and 15.94 kcal/mol in the gas phase, water and diethyl ether (better), respectively. Finally, this work endorsed that purine/HI is an effective catalyst for CO2 fixation with aziridine.

Rational Design of Cobalt Complexes Based on the trans Effect of Hybrid Ligands and Evaluation of their Catalytic Activity in the Cycloaddition of Carbon Dioxide with Epoxide

A series of cobalt complexes are presented as effective catalysts for the synthesis of cyclic carbonates from epoxides and CO2. The catalytic potentials of the cobalt complexes, in combination with...

The metal–organic framework UiO-66 with missing-linker defects: A highly active catalyst for carbon dioxide cycloaddition

Metal-organic frameworks (MOFs) have been confirmed to be a promising material for carbon dioxide capture, while the simultaneous capture and conversion of carbon dioxide over the MOF-based catalysts is furthermore being a hot topic. In this work, we demonstrate that the zirconium-based MOF UiO-66 (UiO for University of Oslo) with missing-linker defects is a highly active catalyst for carbon dioxide cycloaddition with an epoxide, which is a reaction with 100% atom economy and broad industrial uses. A facile, rapid, energy-saving and environmentally friendly argon plasma treatment was employed to create the missing-linker defects in UiO-66 without using hazardous chemicals at atmospheric pressure and temperature below 398 K, whereas the bulk structure of UiO-66 remained stable. The energetic argon plasma species decomposed part of the linkers within UiO-66 structure, leaving unsaturated metal sites. The defect concentration in UiO-66 was tuned by changing the plasma bombardment time. After an argon plasma treatment for 30 min, the number of linker deficiencies per Zr6 cluster can reach up to 2.3. The product yield of the UiO-66 with abundant missing-linker defects increased of ca. 43% over the defect-free UiO-66. The crucial role of the missing-linker defects of UiO-66 in the enhancement of the catalytic activity was confirmed. The present study will be helpful for the future preparation of defective MOFs with potential applications not only for carbon dioxide conversion but also for energy storage and conversion.

Crosslinked Resin-Supported Bifunctional Organocatalyst for Conversion of CO2 into Cyclic Carbonates.

The development of solvent-free, metal-free, recyclable organic catalysts is required for the current chemical fixation of carbon dioxide converted into cyclic carbonates. With the goal of reducing the cost, time, and energy consumption for the coupling reaction of CO2 and epoxides, a series of highly active heterogeneous catalysts, based on a thiourea and quaternary ammonium salt system, are synthesized by using a thiol-ene click reaction under ultraviolet light. Benefitting from synergistic interactions of the electrophilic center (thiourea) and the nucleophilic site (ammonium bromide), the catalysts exhibit excellent catalytic selectivity (99 %) for the cycloaddition of carbon dioxide with a diverse range of epoxides under mild conditions (1.2 MPa, 100 °C). Moreover, the catalyst can be easily recycled by facile filtration and reused for 5 times without noticeable loss of activity and selectivity. This work provides a potential heterogeneous catalyst for the conversion of carbon dioxide into high value-added chemicals with the combined advantages of low cost, easy recovery, and satisfactory catalytic properties.

Hierarchically nanoporous copolymer with built-in carbene-CO2 adducts as halogen-free heterogeneous organocatalyst towards cycloaddition of carbon dioxide into carbonates

A serial of porous polymers incorporating N‑heterocyclic carbene-CO2 adducts (designated as NHC-CO2 adducts) were facilely synthesized via radical polymerization of N-vinylimidazolate and ethyleneglycol dimethacrylate plus post-treatment with dimethyl carbonate (DMC). The polymers possessed tunable chemical structure, large surface area along with abundant meso-macropores and enhanced CO2 uptake which functioned as metal-halogen-free heterogeneous organocatalysts for solvent-free cycloaddition of CO2 to styrene oxide under 10 bar CO2 pressure, exhibiting highly catalytic activity and stable recyclability. Further, turnover frequency (TOF) of 7.1 h−1 (94.3% yield, 12 h) was obtainable under ambient condition, much higher than those of reported metal-halogen-free heterogeneous catalysts, even comparable with existing halogen-containing ones. Furthermore, the catalyst could efficiently convert various epoxides including internal epoxides into corresponding cyclic carbonates under mild condition (1 bar, 70–120 °C). The excellent catalytic performance was ascribed to the appropriate proportion of NHC-CO2 adducts in porous skeleton structure triggered by DMC. A plausible reaction mechanism was proposed to understand NHC-catalyzed fixation of CO2. This study highlights porous organic polymer is a versatile platform of NHC-CO2 adducts to construct eco-friendly solid catalyst towards efficient CO2 conversion.

Efficient Visible-Light Photocatalytic Cycloaddition of CO2 and Propylene Oxide Using Reduced Graphene Oxide Supported BiNbO4

In this study, a series of novel BiNbO₄ and BiNbO₄/reduced graphene oxide (BiNbO₄/r-GO) visible-light photocatalysts were prepared. Pure BiNbO₄ was prepared by simple co-precipitation; on the other hand, BiNbO₄/r-GO composites were prepared by simple mechanical mixing, followed by hydrothermal treatment. The effect of r-GO on the structural, surface morphological, and optical properties of the prepared photocatalysts was investigated using ultraviolet–visible (UV–vis) diffuse reflectance spectroscopy (UV–vis DRS), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) for the determination of the specific surface area and porosity and energy-dispersive X-ray spectroscopy (EDX) for determining the elemental composition. A red shift in optical band gap measurements was observed with the increasing r-GO mass percentage in the prepared BiNbO₄/r-GO composites. Photocatalytic activities of pure BiNbO₄ and the composites were evaluated using the photocatalytic cycloaddition of carbon dioxide to propylene oxide as a model reaction. All the prepared photocatalysts produced cyclic propylene carbonate selectively with no polymeric material observed. The highest photocatalytic efficiency was achieved using BiNbO₄/5% r-GO composite photocatalyst, where the mass percentage of r-GO was 5%.