Glycerol is a valuable feedstock, produced in biorefineries as a byproduct of biodiesel production. Esterification of glycerol with acetic acid yields a mixture of mono-, di-, and triacetins. The acetins are commercially important value-added products with a wide range of industrial applications as fuel additives and fine chemicals.
View Article and Find Full Text PDFThe manufacture of high-value products from biomass derived platform chemicals is becoming an integral part of the biorefinery industry. In this study, we demonstrate a green catalytic process using solvent free conditions for the synthesis of hydroxymethylfurfural (HMF) levulinate from HMF and levulinic acid (LA) over tin exchanged tungstophosphoric acid (DTP) supported on K-10 (montmorillonite K-10 clay) as the catalyst. The structural properties of solid acid catalysts were characterized by using XRD, FT-IR, UV-vis, titration, and SEM techniques.
View Article and Find Full Text PDFThe simultaneous photocatalytic removal of nitrate from aqueous environment in presence of organic hole scavenger using TiO has long been explored. However, the use of unmodified TiO in such reaction resulted in non-performance or release of significant amount of undesirable reaction products in the process, a problem that triggered surface modification of TiO for enhanced photocatalytic performance. Previous studies focused on decreasing rate of charge carrier recombination and absorption of light in the visible region.
View Article and Find Full Text PDFThis study reports the behaviour of SCILL based catalysts in the oxidative S-S coupling of aliphatic and aromatic thiols, namely 1-butanethiol and thiophenol, to dibutyl disulfide and diphenyl disulfide. A range of ionic liquids (1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide) and metal supported catalysts (5% Pt/SiO; 5% Ru/SiO; 5% Ru/C; 5% Pt/OMS-2) were used to prepare the SCILL catalysts and all were found to be active for the reaction following the trend 5% Pt-OMS-2 > 5% Pt/SiO > 5% Ru/C > 5% Ru/SiO. The presence of SCILL catalysts afforded high selectivity to the disulfide, and the activity of the SCILL catalyst was dependent on the ionic liquid used.
View Article and Find Full Text PDFThe Faraday Discussion on the design of new heterogeneous catalysts took place from 4-6 April 2016 in London, United Kingdom. It brought together world leading scientists actively involved in the synthesis, characterisation, modelling and testing of solid catalysts, attracting more than one hundred delegates from a broad spectrum of backgrounds and experience levels - academic and industrial researchers, experimentalists and theoreticians, and students. The meeting was a reflection of how big of an impact the ability to control and design catalysts with specific properties for particular processes can potentially have on the chemical industry, environment, economy and society as a whole.
View Article and Find Full Text PDFPorous manganese oxide (OMS-2) and platinum supported on OMS-2 catalysts have been shown to facilitate the hydrogenation of the nitro group in chloronitrobenzene to give chloroaniline with no dehalogenation. Complete conversion was obtained within 2 h at 25 °C and, although the rate of reaction increased with increasing temperature up to 100 °C, the selectivity to chloroaniline remained at 99.0%.
View Article and Find Full Text PDFTotal neutron scattering has been used to follow the hydrogenation of toluene-d8 to methylcyclohexane-d14 over 3 wt% platinum supported on highly ordered mesoporous silica (MCM-41) at 298 K and under 150 mbar D2 pressure. The detailed kinetic information so revealed indicates that liquid reorganisation inside pores is the slowest step of the whole process. Additionally, the results were compared with the reaction performed under 250 mbar D2 pressure as well as with toluene-h8 hydrogenation using D2 at 150 mbar.
View Article and Find Full Text PDFOrganic solvents, such as cyclohexane, cyclohexene, methylcyclohexane, benzene and toluene, are widely used as both reagents and solvents in industrial processes. Despite the ubiquity of these liquids, the local structures that govern the chemical properties have not been studied extensively. Herein, we report neutron diffraction measurements on liquid cyclohexane, cyclohexene, methylcyclohexane, benzene and toluene at 298 K to obtain a detailed description of the local structure in these compounds.
View Article and Find Full Text PDFTwo stable nanofluids comprising of mixed valent copper(I,II) oxide clusters (<1 nm) suspended in 1-butyl-3-methylimidazolium acetate, [C(4)mim][OAc], and copper(II) oxide nanoparticles (<50 nm) suspended in trioctyl(dodecyl)phosphonium acetate, [P(8 8 8 12)][OAc], were synthesised in a facile one-pot reaction from solutions of copper(II) acetate hydrate in the corresponding ionic liquids. Formation of the nanostructures was studied using (13)C NMR spectroscopy and differential scanning calorimetry (DSC). From a solution of Cu(OAc)(2) in 1-ethyl-3-methylimidazolium acetate, [C(2)mim][OAc], crystals were obtained that revealed the structure of [C(2)mim][Cu(3)(OAc)(5)(OH)(2)(H(2)O)]·H(2)O, indicating the formation of copper hydroxo-clusters in the course of the reaction.
View Article and Find Full Text PDFDetermination of metal oxidation state under relevant working conditions is crucial to understand catalytic behaviour. The reduction behaviour of Pt and Re was evaluated simultaneously as a function of support and solvent in a pressurized reactor (autoclave). The bimetallic catalysts are used in selective hydrogenation of carboxylic acids and amides.
View Article and Find Full Text PDFZnS nanoparticles were synthesized in four component "water in oil" microemulsions formed by a cationic surfactant (cetyltrimethylammonium bromide, CTAB), a cosurfactant (pentanol or butanol), n-hexane and water. The effect of various parameters (nature of cosurfactant, water/surfactant W(0), and alcohol/surfactant P(0)) on the formation and stability of ZnS nanoparticles was investigated thoroughly. UV-Vis spectroscopy was employed to directly follow the formation of ZnS systems in the microemulsions.
View Article and Find Full Text PDFSelective hydrogenation of carboxylic acids to alcohols and alkanes has been achieved under remarkably mild reaction temperatures and H(2) pressures (333 K, 0.5 MPa) using Pt/TiO(2) catalyst.
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