Journal ArticleDOI
Application of CO2-expanded solvents in heterogeneous catalysis: a case study
TLDR
In this paper, the authors applied CO 2 -expanded liquid (CXL) solvent media to heterogeneously catalyzed oxidations and showed that it significantly reduces the use of conventional organic solvents as reaction media and also enhances catalyst stability.Abstract:
CO 2 -expanded liquid (CXL) solvents are known to provide optimum reaction and environmental benefits for certain homogeneously catalyzed oxidations. In this work, CXL solvent media are applied to heterogeneously catalyzed oxidations. The oxidation of cyclohexene is investigated as a model reaction. Conversion/selectivity measurements were made in a stirred batch reactor on a MCM-41 encapsulated iron porphyrin chloride complex ( p =1–127 bar, T =25–50 °C, t =4–12 h), using either dioxygen or iodosylbenzene as oxidant. Neat acetonitrile and CO 2 -expanded acetonitrile are used as reaction media. The pressures required for reaction studies in CO 2 -based media were determined by expansion studies as well as cloud point measurements. For the oxidation with dioxygen, conversion and product yields in CO 2 -expanded acetonitrile (∼30% CO 2 ) almost doubled compared to the neat organic solvent. In contrast, CO 2 -replacement of the organic solvent had a negligible effect on conversion and selectivity values when using iodosylbenzene as oxidant. Our results indicate that CXLs significantly reduce the use of conventional organic solvents as reaction media and also enhance catalyst stability against leaching. These advantages suggest that CXLs are promising media for developing green heterogeneous catalytic processes.read more
Citations
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Journal ArticleDOI
Chiral Salen Complexes: An Overview to Recoverable and Reusable Homogeneous and Heterogeneous Catalysts
Journal ArticleDOI
A critical look at reactions in class I and II gas-expanded liquids using CO2 and other gases
TL;DR: In this article, a short review aims to give a summary of the publications on reactions in class I and II gas-expanded liquids (GXLs) (those with organic or aqueous liquid components).
Journal ArticleDOI
The improved synthesis of carbonated soybean oil using supercritical carbon dioxide at a reduced reaction time
Kenneth M. Doll,Sevim Z. Erhan +1 more
TL;DR: In this paper, a cyclic carbonate of soybean oil (CSO) was synthesized in ∼1/3 of the reaction time reported in the literature using supercritical carbon dioxide (CO2) as the solvent.
Journal ArticleDOI
Silica immobilized ruthenium catalyst used for carbon dioxide hydrogenation to formic acid (I): the effect of functionalizing group and additive on the catalyst performance
TL;DR: In this article, the amine functionalized silica immobilized ruthenium complexes used for CO 2 hydrogenation to formic acid were prepared in an in situ synthesis way.
References
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Journal ArticleDOI
Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism
TL;DR: In this paper, the synthesis of mesoporous inorganic solids from calcination of aluminosilicate gels in the presence of surfactants is described, in which the silicate material forms inorganic walls between ordered surfactant micelles.
Book
Green Chemistry: Theory and Practice
Paul T. Anastas,John C. Warner +1 more
TL;DR: Green Chemistry: What is green chemistry? as discussed by the authors presents the principles of green chemistry and evaluates the impact of chemistry on the environment. But, it is not a complete overview of all of the issues involved in green chemistry.
Journal ArticleDOI
Reactions at supercritical conditions: Applications and fundamentals
TL;DR: A review of chemical reactions in and with supercritical fluids can be found in this paper, where the authors discuss both fundamental studies and applications of reactions at supercritical conditions, with focus on work published after 1985.
Book
Chemical synthesis using supercritical fluids
Philip G. Jessop,Walter Leitner +1 more
TL;DR: In this article, the authors introduce SCF, history, recent trends basic physical properties, phase behaviour and solubility physical properties as related to chemical reactions, reaction equipment design and safety extraction using SCFs precipitation and crystallization techniques surfactants for SCFs.