Efficient Catalyst For Chemical Fixation Research Articles

Retraction Note: A porous Er(III)–organic framework as a highly efficient catalyst for chemical fixation of CO2 and treatment activity on senile deafness via inducing the cochlear hair cell apoptosis

Retraction Note: A porous Er(III)–organic framework as a highly efficient catalyst for chemical fixation of CO2 and treatment activity on senile deafness via inducing the cochlear hair cell apoptosis

Experimental and computational studies of Zn (II) complexes structured with Schiff base ligands as the efficient catalysts for chemical fixation of CO2 into cyclic carbonates

The present work aimed at comparably studying the catalytic performance of Zn (II) complexes applied as the efficient catalysts in accelerating the transformation of CO2 into cyclic carbonates. The physicochemical properties of the synthesized complexes were determined by XRD, NMR, FT-IR, TGA, NH3-TPD, CO2-adsorption. The synthesized samples were found to possess the Lewis acid/basic sites derived from the zinc ions and nitrogen-containing ligands, which can synergistically catalyze the coupling reaction. In addition, the sample containing iodide ion ligands showed the highest catalytic performance compared with other Zn (II) complexes, suggesting that the amount and distribution of the Lewis acid sites were not the primary factors for determining the catalytic activity, and the difference in activity of halogen ion ligands (I−, Br−, Cl−) has a larger influence on the coupling process, which made the CO2 insertion and ring closure of the formed intermediate more easily occur when iodide ion ligands participated. It can be drawn that the catalytic activity of the Zn (II) complexes was simultaneously associated with halide ion ligands and substitution group of the ligand. Moreover, 98.62% conversion of epichlorohydrin (ECH) and 96.97% selectivity to chloropropene carbonate (TOF=56.65 h − 1) was achieved at the optimal operation parameters (110 °C, 2.5 MPa, 8 h, 1.25 wt.% catalyst of ECH). Furthermore, the proposed pathway of CO2 coupling with epoxide was confirmed by DFT calculation, with the result confirming that the process of epoxide ring opening was the key step for the coupling reaction.

Zinc(II)(Pyridine‐Containing Ligand)] Complexes as Single‐Component Efficient Catalyst for Chemical Fixation of CO2 with Epoxides

AbstractThe reaction between epoxides and CO2 to yield cyclic carbonates is efficiently promoted under solvent‐free and relatively mild reaction conditions (0.5 mol % catalyst loading, 0.8 MPa, 125 °C) by zinc(II) complexes of pyridine containing macrocyclic ligands (Pc−L pyridinophanes). The zinc complexes have been fully characterized, including X‐ray structural determination. The [Zn(II)X(Pc−L)]X complexes showed good solubility in several polar solvents, including cyclic carbonates. The scope of the reaction under solvent‐free conditions has been studied and good to quantitative conversions with excellent selectivities have been obtained, starting from terminal epoxides. When solvent‐free conditions were not possible (solid epoxides or low solubility of the catalyst in the oxirane) the use of cyclic carbonates as solvents has been successfully investigated. The remarkable stability of the catalytic system has been demonstrated by a series of consecutive runs.

RETRACTED ARTICLE: A porous Er(III)–organic framework as a highly efficient catalyst for chemical fixation of CO2 and treatment activity on senile deafness via inducing the cochlear hair cell apoptosis

A microporous Er(III)-based metal–organic framework (MOF), whose chemical formula can be written as {[Er(TCPB)(H2O)]·dioxane·0.5H2O}n, has been formed from the tripodal ligand 1,3,5-tris(4-carbonylphenyloxy)benzene (H3TCPB) by solvothermal synthesis and determined by the single crystal X-ray diffraction and the elemental analysis. With the aid of microporous framework and abundant catalytic sites of open Er(III) sites, the activated 1 is a special catalyst for the synthesis of cyclic carbonates from carbon dioxide and epoxy compounds under the cocatalyst TBAB and gently solvent-less conditions. The treatment activity of the compound on the senile deafness, as well as the influence of the compound on the cochlear hair cell death was explored. Firstly, the cell apoptosis of the cochlear hair cells was estimated via CCK-8 assay. Next, the activation of the caspase-3,8 was evaluated with western blot.

Imidazolium ionic liquid functionalized UiO-66-NH2 as highly efficient catalysts for chemical fixation of CO2 into cyclic carbonates

Imidazolium ionic liquids functionalized UiO-66-NH 2 MOFs were synthesized by two different approach, further applied as efficient catalysts for the catalytic conversion of CO 2 into cyclic carbonates. The functionalized UiO-66-NH 2 were investigated using various characterization technologies including XRD, NMR, FT-IR, XPS, TG-DTG, TEM, N 2 -adsorption, and NH 3 -TPD. The octahedron structure of UiO-66-NH 2 becomes rough after UiO-66-NH 2 interacted with 1-(4-carboxybutyl)-3-methylimidazolium bromide via amidation, while some small grains were formed around UiO-66-NH 2 species when UiO-66-NH 2 was functionalized by 1-(3-sulfopropyl)-3-methylimidazolium bromide ([SPMIM]Br) via the H 2 N– and HSO 3 – interaction. Moreover, when [SPMIM]Br was grafted onto the surface of UiO-66-NH 2 , a higher catalytic activity was found to exhibit 98.12% conversion of epichlorohydrin (ECH) and 98.23% selectivity to chloropropene carbonate (CPC) under optimized conditions (Initial pressure 2.5 MPa, 1.2 wt% catalyst of ECH, 95 °C, reaction time 8 h). No significant deactivation of the catalyst was observed after the [SPMIM]Br functionalized UiO-66-NH 2 was reused three times. Furthermore, several additional coupling reactions were investigated with other epoxides as substrates. Chemical fixation of CO 2 into cyclic carbonates over ionic liquid functionalized UiO-66-NH 2 . • Two different approach was applied for the synthesis of functionalized UiO-66-NH 2 . • CO 2 can be efficiently converted into various cyclic carbonates over functionalized UiO-66-NH 2 . • 98.12% conversion of epichlorohydrin and 98.23% selectivity to chloropropene carbonate was obtained. • The difference of imidazolium ionic liquids was also studied by DFT calculations.

Novel mono-and bi-functional phosphonium salts deriving from toxic phosphine off-gas as efficient catalysts for chemical fixation of CO2

Utilizing phosphine (PH3) tail gas as starting feedstock, a series of novel mono-and bifucntional phosphonium compounds (P+(CH2CH2CN)3RX−, X= Br, I) was prepaed by a sustainable preparation route. The newly prepared phosphonium halides show high thermal stability and their degradation temperature are far higher than that of CO2 chemical fixation. The mono-fucntional phosphonium salts combinate with ZnBr2 to form an efficient Lewis acid/base type catalytic system for CO2 chemical fixation and the bifucntional phosphonium salts alone shows same catalytic effects. The effects of temperature, CO2 pressure, composition of the catalytic system on coupling reaction of CO2 with epoxides are investigated to evaluate the catalytic performance. The results illustrate that 96.7% cyclic Carbonate yield can be obtained in presence of ZnBr2/P+(CH2CH2CN)3C4H9Br− (molar ratio = 1:10) under 120 °C, 1.5MPa of CO2 pressure in solvent-free condition, menawhile bifuntional phiospohonium salt Br-P+(CH2CH2CN)3C2H4COOH alone shows better catalytic perofromance.

A Double-Walled Porous Metal-Organic Framework as a Highly Efficient Catalyst for Chemical Fixation of CO2 with Epoxides.

A double-walled MOF [Zn5(μ3-OH)2(DBTA)2(H2O)4]·solvents [1, H4DBTA = 2,2'-dihydroxy-1,1'-binaphthyl-3,3',6,6'-tetrakis(4-benzoic acid)] has been designed and constructed based on a rare Zn5 cluster. The resultant sample has enrichment of porous structure with high BET and Langmuir surface area. By virtue of multiaperture structure and plentiful catalytic sites of Brønsted (-OH) and Lewis acidic (ZnII), MOF 1 is a unique catalyst to synthesize cyclic carbonates from CO2 and epoxides with preferable repeatability.

ONO pincer type ligand complexes of Al(III) as efficient catalyst for chemical fixation of CO2 to epoxides at atmospheric pressure

Carbon dioxide, the main cause of environmental pollution, its utilization to produce valuable products is of utmost interest. A series ONO pincer hydrazone based most active mono-nuclear Al(III) complexes were successfully synthesized and characterized with the help of NMR, IR, mass spectrometry and only complex 2a was confirmed by single-crystal analysis. The synthesized Al(III) complexes were then employed as capable catalysts for the solvent-free chemical fixation of CO2 with epoxides at atmospheric pressure and could be reused five times without loss of any catalytic activity. In addition, the catalytic mechanism was investigated by analyzing intermediates via 1H NMR, 13C NMR, and mass MALDI-TOF. The excellent catalytic performance could be due to simultaneous attack and the opening of the epoxide by metal centers to form an alkoxide ion which activates the CO2 the same time.

(CH3)2NH2][M(COOH)3] (M=Mn, Co, Ni, Zn) MOFs as highly efficient catalysts for chemical fixation of CO2 and DFT studies

The present work aimed to investigate the differences of metal species of [(CH3)2NH2][M(COOH)3](DMA-MF, M = Mn, Co, Ni, Zn) compounds being applied as highly efficient catalysts for enhancing the cycloaddition of CO2 with epoxides. The properties of the as-prepared compounds were systematically investigated via characterizations such as XRD, FT-IR, Raman, XPS, CO2-adsorption, TG-DTG, and CO2/NH3-TPD. The DMA-MnF sample was observed with the highest catalytic activity among the studied MOFs, of which metal node (served as Lewis acid sites) and DMA+ groups (functionalized as Lewis basic sites) within the DMA-MF play a synergistically catalytic effect on the coupling process. Furthermore, when the coupling reaction was carried out at 120 °C for 6 h in presence of 2.0 wt.% PO catalyst under 2.0 MPa, 99.68% conversion of PO and 98.01% yield of propylene carbonate (PC) were perfectly obtained over DMA-MnF compound. In addition, the CO2 coupling with 1, 2-epoxybutane, allyl-glycidyl ether, epichlorohydrin, and styrene oxide were also accomplished under the same conditions. Finally, the DFT calculation was utilized to reveal the appropriate reaction path.

2-Methylimidazole Modified Co-BTC MOF as an Efficient Catalyst for Chemical Fixation of Carbon Dioxide

[(CH3)2NH2][Co3(BTC)(HCOO)4(H2O)]·H2O (Co-BTC) was synthesized under solvothermal conditions, further used as the precursor for the synthesis of 2-methylimidazole modified Co-BTC (2MeIm@Co-BTC-x). The characteristics of 2MeIm@Co-BTC-x were systematically characterized by various technologies including XRD, FESEM, FT-IR, XPS, N2-adsorption, TG-DTG and CO2/NH3-TPD. It was found that except for the crystal faces (0 1 1) and (− 1 0 2) corresponding to ZIF-67 and Co-BTC, a new crystal phase appeared at 12.22o for the modified Co-BTC, which may be attributed to the coordination between 2MeIm and unsaturated Co ions of Co-BTC. Interestingly, a new structure of hexagonal prisms together with hierarchical porous were also formed for the modified Co-BTC. Besides, when this composite was explored as a heterogeneous catalyst for catalytic conversion of carbon dioxide with epichlorohydrin (ECH) as probe, an obvious enhancement in catalytic activity was obtained compared with the fresh Co-BTC, suggesting that 2MeIm ligands within the modified Co-BTC played a great role on the coupling process. Furthermore, 97.21% of ECH conversion and 98.79% of chloropropene carbonate selectivity were gained over 2MeIm@Co-BTC-1.0 under optimal conditions (3.0 MPa, 90 °C, 5 h, 0.75 wt% catalyst of ECH). Additionally, only a slight decrease in catalytic activity was found after the optimal sample was reused three times. Finally, a mechanism for interpreting the coupling process of carbon dioxide cycloaddition with epoxide was proposed. One-pot catalytic conversion of CO2 into cyclic carbonate over 2-methylimidazole modified Co-BTC

Metal β-diketonate complexes as highly efficient catalysts for chemical fixation of CO2 into cyclic carbonates under mild conditions.

The potential of metal β-diketonate complexes for the catalysis of the chemical fixation of CO2 into cyclic carbonates at 1 atm CO2 and near room temperature was demonstrated. Their potential for the capture and simultaneous conversion of CO2 in a dilute CO2 stream was also determined. The catalysts were easily synthesized and commercially available. Therefore, this CO2 transformation was less energy- and material-consuming, which made this reaction closer to true "green" chemistry.

Zn2(C9H3O6)(C4H5N2)(C4H6N2)3 MOF as a highly efficient catalyst for chemical fixation of CO2 into cyclic carbonates and kinetic studies

Zn2(C9H3O6)(C4H5N2)(C4H6N2)3 (Zn-BTC-2MeIm) was hydrothermally synthesized and employed as a highly efficient catalyst for CO2 coupling with epichlorohydrin (ECH). Various techniques such as XRD, FT-IR, XPS, TG-DTG, NH3/CO2-TPD were employed for characterizing the compound. Interestingly, TG profile illustrated the Zn-BTC-2MeIm was stable above 200°C. The highest catalytic activity of 98.93% conversion of ECH and 98.32% selectivity to chloropropene carbonate was observed under the optimum conditions (100°C, 120mesh, 1000rpm, 3.0MPa, 6h, 0.75wt.% of ECH). Besides, the recyclability results exhibited Zn-BTC-2MeIm compound could be reused no less than three times with a slight reduction in its catalytic ability. Moreover, coupling results of CO2 with other epoxides showed this compound could efficiently convert various epoxides into cyclic carbonates. Finally, the investigation of the kinetic exhibited the law of CO2 coupling with ECH was coincident with the first order kinetic and the activation energy (Ea) was to be 113.38kJ/mol.

Dual-ionic liquid system: an efficient catalyst for chemical fixation of CO2 to cyclic carbonates under mild conditions

An easily prepared novel dual-ionic liquid system can catalyze the reactions of CO2 and epoxides to form cyclic carbonates under mild conditions (1 atmos CO2, T = 30–60 °C) with excellent yields in the absence of any solvents or additives.

3D-monoclinic M–BTC MOF (M = Mn, Co, Ni) as highly efficient catalysts for chemical fixation of CO2 into cyclic carbonates

[(CH3)2NH2][M3(BTC)(HCOO)4(H2O)].H2O (M–BTC, M=Mn, Ni, Co) were prepared under hydrothermal conditions and used as highly efficient catalysts for cycloaddition of CO2 with epichlorohydrin (ECH). The microstructure and physicochemical properties of the compounds were determined by PXRD, FT-IR, XPS, N2-adsorption, TG–DSC, NH3–TPD and CO2–TPD. 98.01% conversion of ECH and 96.05% selectivity to chloropropene carbonate was obtained over the Mn–BTC under the optimized reaction conditions (105°C, 3.0MPa, 9h, 1.5wt.% of ECH). Besides, the recyclability result exhibited the Mn–BTC compound can be utilized as least three times with a slight reduction in its catalytic ability. In addition, cycloaddition of CO2 with other epoxides and DFT calculation were also performed. The result exhibited the yield followed the order: ECH>1, 2-epoxybutane>propene oxide>Allyl glycidyl ether, which was mainly determined by the energy of reaction.

Carbon nitride as efficient catalyst for chemical fixation of CO2 into chloropropene carbonate: Promotion effect of Cl in epichlorohydrin

As an abundant, nontoxic, cheap, and renewable carbon resource, carbon dioxide (CO2) has drawn much attention in recent years. The chemical fixation of CO2 for various synthetic transformations is a hot topic in current researches. In the present work, three kinds of carbon nitride (C3N4) were prepared and tested for the chemical fixation of CO2 to chloropronene carbonate (CPC). These catalysts were characterized by means of XRD, SEM, BET, IR, and XPS. The activity test demonstrated that u-C3N4 presents the best catalytic activity, which was attributed to the large amount of edge defects in the structure and its higher surface area. The superior reactivity of epichlorohydrin (ECH) compared with other epoxide was derived from the Cl atom in its structure, which can act as a co-catalyst for the reaction and activate epoxide group in ECH as well. The best result was obtained at 120°C, 2MPa initial CO2 pressure in 5hours with an ECH conversion of 98.31% and CPC selectivity of 98.01%. The catalyst can be reused for five cycles with only minimal decrease in catalytic activity. Moreover, based on the experimental and characterization results a possible reaction mechanism was proposed.

Multilayered supported ionic liquids bearing a carboxyl group: Highly efficient catalysts for chemical fixation of carbon dioxide

A series of carboxyl functional multilayered supported ionic liquids were synthesized and used as efficient catalysts for chemical fixation of carbon dioxide to form cyclic carbonates without any co-solvent and co-catalyst. The excellent yield and selectivity of cyclic carbonate were given with using PS-ImEImECOOHI2 as a catalyst at 120°C and 2.0MPa for 2.0h. The synergistic effect of anions and cations in multilayered supported ionic liquids contributed to the good catalytic activity for the synthesis of cyclic carbonates from carbon dioxide and epoxide. Furthermore, the catalyst showed excellent stability and could be reused up to ten times without any significant loss of catalytic activity.

ChemInform Abstract: Nicotine‐Derived Ammonium Salts as Highly Efficient Catalysts for Chemical Fixation of Carbon Dioxide into Cyclic Carbonates under Solvent‐Free Conditions.

AbstractA newly prepared nicotine‐derived ammonium salt is applied for the first time as a recyclable and efficient catalyst for the coupling of carbon dioxide and epoxides to form cyclic carbonates at low pressure without using additional organic solvents.

ChemInform Abstract: Zn‐Based Ionic Liquids as Highly Efficient Catalysts for Chemical Fixation of Carbon Dioxide to Epoxides.

AbstractThe introduced catalyst can be reused at least four times without significant loss of reactivity.

Zn-based ionic liquids as highly efficient catalysts for chemical fixation of carbon dioxide to epoxides

Novel Zn-TSILs catalysts were developed, which showed high activity towards the cycloaddition of CO2 to epoxides due to synergetic effects.

Nicotine-derived ammonium salts as highly efficient catalysts for chemical fixation of carbon dioxide into cyclic carbonates under solvent-free conditions

Ammonium salts based on nicotine proved to be highly efficient and recyclable catalysts for the synthesis of cyclic carbonates from epoxides and CO2 without the utilization of any organic solvent and any additives.