F:Flammable;1678-91-7Relevant articles and documents
Nanoreactors based on hydrophobized tubular aluminosilicates decorated with ruthenium: Highly active and stable catalysts for aromatics hydrogenation
Glotov, Aleksandr,Novikov, Andrei,Stavitskaya, Anna,Nedolivko, Vladimir,Kopitsyn, Dmitry,Kuchierskaya, Alexandra,Ivanov, Evgenii,Stytsenko, Valentine,Vinokurov, Vladimir,Lvov, Yuri
, p. 33 - 42 (2021)
Industrial hydrogenation catalysts must be not only selective and active but also resistant to feedstock impurities, including water. We report the strategy of preparing catalytic core-shell nanoreactors based on hydrophobized aluminosilicate nanotubes loaded with ruthenium. The modification of halloysite with alkyltriethoxysilanes enhances hydrophobicity of the clay nanotubes (water contact angle up to 122°) and enables their selective loading with 4-nm ruthenium particles. Such a core-shell tubular nanoreactors provide shielding of active sites from deactivation by admixed water and prevent metal leaching. Produced mesoscale catalysts were active in the hydrogenation of aromatics both in organic and aqueous media at 80 °C and a hydrogen pressure of 3 MPa. Benzene hydrogenation in the biphasic system with water resulted in a complete conversion with 100 % selectivity to cyclohexane over halloysite modified by C18-triethoxysilane supported ruthenium catalyst with turnover frequency (TOF) of 4371 h?1. This catalytic system remained stable after ten cycles of benzene hydrogenation, providing 98 % conversion. The demonstrated synthetic strategy is promising for the design of industrial catalysts for the hydroprocessing water-containing organic feedstock and may be upscaled due to the abundant availability of halloysite clay nanotubes.
Surfactant-stabilized aqueous iridium(0) colloidal suspension: An efficient reusable catalyst for hydrogenation of arenes in biphasic media
Mevellec, Vincent,Roucoux, Alain,Ramirez, Esther,Philippot, Karine,Chaudret, Bruno
, p. 72 - 76 (2004)
Aqueous suspensions of iridium nanoparticles produced by the chemical reduction of IrCl3 assisted by sonication, in the presence of N,N-dimethyl-N-cetyl-N-(2-hydroxyethyl)ammonium chloride salt as surfactant, have shown an efficient activity for the catalytic hydrogenation of various aromatic derivatives in biphasic media under mild conditions. These nanocatalysts can be reused for further runs with a total conservation of activity and provided significant catalytic lifetime for anisole hydrogenation in pure water with 3000 total turnover (TTO).
REACTIONS OF FREE RADICALS WITH MONOETHYLDICHLOROCHROMIUM(III) TRIS(TETRAHYDROFURANATE)
Sustmann, Reiner,Altevogt, Rudolf
, p. 5165 - 5166 (1981)
?-Ethyl-chromium(III)dichloride * 3 THF reacts with free radicals by formation of a transient paramagnetic complex which decomposes giving the combination product of alkyl ligand and radical.
Catalytic dehydrogenation of cyclooctane with titanium, zirconium and hafnium metallocene complexes
Taubmann, Sandra,Denner, Christine E.,Alt, Helmut G.
, p. 2005 - 2019 (2009)
Metallocene complexes in combination with cocatalysts like methylalumoxane (MAO) are not only excellent catalysts for olefin polymerization but also appropriate catalysts for the activation of alkanes in homogeneous (autoclave) and heterogeneous (fixed be
On the influence of diphosphine ligands on the chemical order in small RuPt nanoparticles: Combined structural and surface reactivity studies
Lara, Patricia,Ayvali, Tugce,Casanove, Marie-Jose,Lecante, Pierre,Mayoral, Alvaro,Fazzini, Pier-Francesco,Philippot, Karine,Chaudret, Bruno
, p. 372 - 382 (2013)
Diphenylphosphinobutane (dppb) stabilized bimetallic RuPt nanoparticles were prepared by co-decomposition of [Ru(COD)(COT)] [(1,5-cyclooctadiene)(1,3,5- cyclooctatriene)ruthenium] and [Pt(CH3)2(COD)] [dimethyl(1,5-cyclooctadiene) platinum(ii)] organometallic precursors under mild conditions (room temperature, 3 bar of dihydrogen) and in the presence of dppb. The determination of the nanoparticles' chemical composition was made possible thanks to a combination of several characterization techniques (HREM, STEM-HAADF, WAXS, EXAFS, IR, NMR) associated with surface reactivity studies based on simple catalytic reactions. The obtained nanoparticles display a ruthenium rich core and a disordered shell containing both ruthenium and platinum. The results were compared with those obtained on nanoparticles of similar size and composition but not containing ligands. The complexity observed in the present structure of these nanoparticles arises from the high chemical affinity of the diphosphine ligand used as a stabilizer for both metals.
Small bite-angle 2-phosphinophosphinine ligands enable rhodium-catalysed hydroboration of carbonyls
Newland, Robert J.,Lynam, Jason M.,Mansell, Stephen M.
, p. 5482 - 5485 (2018)
Two Rh complexes of the 2-phosphinophosphinine ligand 2-PPh2-3-Me-6-SiMe3-C5H2P (1) were prepared: dinuclear trans-[{Rh(CO)(Cl)(μ-1)}2] (2) and chelating [Rh(1)(COD)][B(ArF)4] (3). Despite the widespread use of Rh catalysts for the hydroboration of alkenes, 3 is reported to be the first Rh catalyst for ketone and ketimine hydroboration, with high activity observed at 0.1 mol% loading.
A Comparison of Ruthenium-Catalysed Arene Hydrogenation Reactions in Water and 1-Alkyl-3-methylimidazolium Tetrafluoroborate Ionic Liquids
Dyson, Paul J.,Ellis, David J.,Henderson, William,Laurenczy, Gábor
, p. 216 - 221 (2003)
The hydrogenation of benzene and other arene substrates under biphasic conditions is evaluated using the catalyst precursor Ru(η6-C 10H14)(pta)Cl2 (pta = 1,3,5-triaza-7- phosphaadamantane) immobilised in water and 1-alkyl-3-methylimidazolium tetrafluoroborate ionic liquids. The effect that contamination of the 1-alkyl-3-methylimidazolium tetrafluoroborate ionic liquids with chloride has on the hydrogenation reaction has also been examined. Of the immobilisation solvents tested the optimum solvent was found to be chloride-free 1-butyl-3-methylimidazolium tetrafluoroborate. Catalytic turnovers in this solvent are highest, and in general, turnovers for the hydrogenation reactions follow the trend: chloride-free 1-butyl-3-methylimidazolium tetrafluoroborate > water > chloride-contaminated 1-butyl-3-methylimidazolium tetrafluoroborate.
Catalytic hydrogenation of aromatics under biphasic conditions: Isolation and structural characterisation of the cluster intermediate [(η6-C6Me6)2(η 6-C6H6)Ru3(μ2-H) 2(μ2-OH)(μ3-O)]+
Faure, Matthieu,Vallina, Ana Tesouro,Stoeckli-Evans, Helen,Süss-Fink, Georg
, p. 103 - 108 (2001)
The water-soluble cluster cation [(η6-C6Me6)2(η 6-C6H6)Ru3(μ2-H) 3(μ3-O)]+ (2) catalyses the hydrogenation of benzene and benzene derivatives to give the corresponding cyclohexanes under biphasic conditions. The catalytic activity of 2 depends markedly on the substrate, an extremely high activity being observed for ethylbenzene. The cationic species present in the catalytic mixture of the ethylbenzene hydrogenation could be isolated as the tetrafluoroborate salt and characterised as the cation [(η6-C6Me6)2(η 6-C6H6)Ru3(μ2-H) 2(μ2-OH)(μ3-O)]+ (3). With 3 as the catalyst, the catalytic activity is also much higher for other benzene derivatives.
Alkyne-Functionalized Ruthenium Nanoparticles: Impact of Metal-Ligand Interfacial Bonding Interactions on the Selective Hydrogenation of Styrene
Zhang, Fengqi,Fang, Jingjing,Huang, Lin,Sun, Wenming,Lin, Zhang,Shi, Zhenqing,Kang, Xiongwu,Chen, Shaowei
, p. 98 - 104 (2019)
In the present study, ruthenium nanoparticles functionalized with terminal and internal alkynes were prepared, and it was found that internal alkynes formed a η2 side-on configuration on the surface of ruthenium nanoparticles, in sharp contrast to the ruthenium-vinylidene interfacial bonds for terminal alkynes. For the nanoparticles capped with terminal alkyne, hydrogenation of both the vinyl moiety and phenyl ring occurred, whereas selective hydrogenation of the vinyl moiety was observed with internal alkyne-functionalized nanoparticles. This work highlights the importance of the metal-organic interface in the rational design and engineering of the nanoparticle catalyst for organic synthesis.
Preparation of a PdRuNi/C tri-metallic nanocatalyst and its excellent catalytic performance for ethylbenzene hydrogenation reaction
Pei, An,Ruan, Luna,Liao, Jianhua,Zhang, Huan,Wang, Jiexiang,Yang, Kai,Liu, Zhiping,Zhu, Lihua,Chen, Bing Hui
, p. 17306 - 17314 (2019)
Herein, Ni/C was prepared at room temperature (RT) by liquid chemical reduction by using hydrazine hydrate as the reducing agent. The impregnation method was adopted to deposit precious metals on carbon black (C) to obtain the Pd/C, Ru/C monometallic and PdRu/C bimetallic catalysts. The PdNi/C, RuNi/C bimetallic and PdRuNi/C tri-metallic catalysts were obtained through a chemical replacement reaction method. The as-prepared catalysts were characterized by inductively coupled plasma mass spectrometry (ICP-MS), X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution TEM (HRTEM), high-angle annular dark-field scanning TEM (HAADF-STEM) and STEM energy dispersive X-ray spectroscopy (STEM-EDS) elemental mapping and line-scanning, scanning electron microscopy (SEM) and SEM-EDS, X-ray photoelectron spectroscopy (XPS) and high-sensitivity low-energy ion scattering spectroscopy (HS-LEIS) techniques, which proved that PdRu islands were supported on the Ni/Ni(OH)2 nanoparticles (NPs) (PdRu-on-Ni/Ni(OH)2 NPs) in PdRuNi/C. The results revealed that the PdRuNi/C catalyst showed the most excellent catalytic performance for ethylbenzene hydrogenation under mild reaction conditions mainly owing to the synergistic effect among the Pd, Ru and Ni related species. The PdRuNi/C catalyst also exhibited good stability in ethylbenzene hydrogenation.
