The effect of ionic liquids on product yield and catalyst stability

Wong, Hau-to; Han, Shaojie; Livingston, Andrew G.

doi:10.1016/j.ces.2005.08.019

Cited by 36 publications

(28 citation statements)

References 5 publications

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“…(18) and (19) lead to asymptotic values of Y COE,max of 32 % and 20 %, compared to the measured value of 35 % (see Fig. 11).…”

Section: Influence Of Pore Diffusion On Selectivity Of Cod Hydrogenationmentioning

confidence: 85%

“…(18) and (19) lead to asymptotic values of Y COE,max (strong limitation by pore diffusion) of only 20 % and 10 %. This strong decrease with increasing resistance to pore diffusion (and thus increasing particle diameter) is also measured for particle sizes up to 1.5 mm (see Fig.…”

Section: Influence Of Pore Diffusion On Selectivity Of Cod Hydrogenationmentioning

confidence: 95%

“…For applications of ILs in the field of catalysis, two directions recently discussed in the literature are particularly attractive: -ILs are not only interesting solvents for homogeneous catalysis but also for heterogeneously catalyzed reactions [19][20][21]. For example, Xu et al [21] showed that ILs are excellent media for the hydrogenation of halonitrobenzenes to the corresponding haloanilines over Raney nickel, carbon-supported platinum and palladium.…”

Section: Introductionmentioning

confidence: 99%

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Solid Catalyst with Ionic Liquid Layer (SCILL) – A New Concept to Improve Selectivity Illustrated by Hydrogenation of Cyclooctadiene

et al. 2007

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A new concept of a solid catalyst with ionic liquid layer (SCILL) as a novel method to improve the selectivity of heterogeneous catalysts is presented. The sequential hydrogenation of cyclooctadiene (COD) to cyclooctene (COE) and cyclooctane on a commercial Ni catalyst coated with the ionic liquid [BMIM][n-C 8 H 17 OSO 3 ] was tested as first model system. Compared to the original catalyst, the coating of the internal surface with the ionic liquid (IL) strongly enhances the maximum intrinsic COE yield from 40 to 70 %. This effect is already achieved for a pore filling degree of only 10 % and cannot be explained by pore diffusion, as shown by experiments with different particle sizes and theoretical considerations. The IL layer is very robust and no leaching into the organic phase was detectable.

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“…(18) and (19) lead to asymptotic values of Y COE,max of 32 % and 20 %, compared to the measured value of 35 % (see Fig. 11).…”

Section: Influence Of Pore Diffusion On Selectivity Of Cod Hydrogenationmentioning

confidence: 85%

Section: Influence Of Pore Diffusion On Selectivity Of Cod Hydrogenationmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Solid Catalyst with Ionic Liquid Layer (SCILL) – A New Concept to Improve Selectivity Illustrated by Hydrogenation of Cyclooctadiene

et al. 2007

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“…Their remarkable chemical and physical characteristics encouraged both academic and industrial chemists to explore their use in diverse domains such as chemical analysis, 16 liquid-liquid extraction processes, 17 electrochemistry, 18 engineering fluids, 19 and as recyclable alternatives to aprotic solvents in organometallic reactions. 20 SO 3 H-functionalized ILs can be used as highly efficient acid catalysts and have been receiving extensive interest as green substitute for H 2 SO 4 , HF and AlCl 3 catalysts in chemical processes.…”

Section: -15mentioning

confidence: 99%

Preparation, Characterization and First Application of Aerosil Silica Supported Acidic Ionic Liquid as a Reusable Heterogeneous Catalyst for the Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones

Yassaghi¹,

Davoodnia²,

Allameh³

et al. 2012

Bulletin of the Korean Chemical Society

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A new heterogeneous acidic catalyst was successfully prepared by impregnation of silica (Aerosil 300) by an acidic ionic liquid, named 1-(4-sulfonic acid)butylpyridinium hydrogen sulfate [PYC 4 SO 3 H][HSO 4 ], and characterized using FT-IR spectroscopy, the N 2 adsorption/desorption analysis (BET), thermal analysis (TG/ DTG), and X-ray diffraction (XRD) techniques. The amount of loaded acidic ionic liquid on Aerosil 300 support was determined by acid-base titration. This new solid acidic supported heterogeneous catalyst exhibits excellent activity in the synthesis of 2-aryl-2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation reaction of 2-aminobenzamide with aromatic aldehydes under solvent-free conditions and the desired products were obtained in very short reaction times with high yields. This catalyst has the advantages of an easy catalyst separation from the reaction medium and lower problems of corrosion. Recycling of the catalyst and avoidance of using harmful organic solvent are other advantages of this simple procedure.

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“…The consequent loss of ionic liquid into the extraction solvent can create problems in downstream processing. Apart from these considerations, ILs tend to have much higher viscosities than organic solvents, which introduces engineering issues, such as uneven concentration and temperature distributions, due to mass and energy transfer limitations within the reactors [43].…”

Section: Reactionsmentioning

confidence: 99%

The Path Ahead for Ionic Liquids

2007

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Ionic liquids are designer molecules which can efficiently replace the conventional organic solvents used in chemical processes and operations. Although a number of such applications have been reported in the literature for almost a decade, very few have actually been commercialized. This paper details the different applications claimed and examines the issues and barriers which obstruct the rapid commercialization of ionic liquids. It identifies further courses of action required for the assessment and realization of the advantages of ionic liquids. PreambleFor the past ten years, ionic liquids (ILs) have been looked upon as a revolutionary replacement for conventional organic solvents, as a medium which can be designed and used to carry out a number of chemical reactions and operations at comparatively lower temperature and pressure conditions, and which do not affect the environment. However, thus far only a few ILs have been manufactured and utilized on a commercial scale. This paper examines the claimed uses of ILs, the issues and barriers for their commercialization and the course of action required to explore their utilization. Ionic LiquidsIonic liquids are defined as room temperature fluids composed entirely of ions that are typically large organic cations and small inorganic or organic anions [1]. The thermodynamics and reaction kinetics of processes carried out in ionic liquids are different from those in conventional media. This creates new opportunities for catalytic reactions, separations, electrochemistry and combined reaction/separation processes. ILs have negligible vapor pressures near room temperature and the emission of volatile organic compounds, which is substantial for conventional organic solvents, is negligible for ILs. This leads to cleaner chemical processes and operations.Ionic liquid salts can be mixed with other salts including inorganic salts to form multicomponent ILs. Suitable cations and anions can be chosen to obtain ILs with the desired properties for specific application and there can be innumerable mixtures. It is possible to design an IL for a particular application by combining a cation with an organic or inorganic anion, as shown in Fig. 1, to obtain desired melting points, viscosity, density, hydrophobicity, miscibility, etc. The estimated number of IL mixtures currently available is 1018 [2]. PropertiesBy choosing the anion or alkyl chain of the cation, one can vary the hydrophobicity, viscosity, density, and solvation of the ionic liquid system. The contamination of ILs by impurities such as water, halides, and metal ions often affects the physical properties. The physical and thermodynamic properties of some ILs are given in Tab. 1 [3] 1) . DensityIonic liquids generally have a higher density than water. Traces of water in the ionic liquids appear to act as a diluent, and therefore, lower the density. However, such traces have a relatively small effect. ViscosityViscosity is an important physical property. ILs are generally viscous, compared to molecular solvents. How...

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The effect of ionic liquids on product yield and catalyst stability

Cited by 36 publications

References 5 publications

Solid Catalyst with Ionic Liquid Layer (SCILL) – A New Concept to Improve Selectivity Illustrated by Hydrogenation of Cyclooctadiene

Solid Catalyst with Ionic Liquid Layer (SCILL) – A New Concept to Improve Selectivity Illustrated by Hydrogenation of Cyclooctadiene

Preparation, Characterization and First Application of Aerosil Silica Supported Acidic Ionic Liquid as a Reusable Heterogeneous Catalyst for the Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones

The Path Ahead for Ionic Liquids

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