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.
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.
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.
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.
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.
Enhancing the catalytic activity of Ru NPs deposited with carbon species in yolk-shell nanostructures
Guo, Miao,Lan, Guojun,Peng, Juan,Li, Mingrun,Yang, Qihua,Li, Can
, p. 10956 - 10963 (2016)
The synthesis of metal NPs with a well-defined size, shape and composition provides opportunities for tuning the catalytic performance of metal NPs. However, the presence of a stabilizer on the metal surface always blocks the active sites of metal NPs. Herein, we report an efficient method to remove the stabilizer on the metal surface via H2 pyrolysis with Ru-poly(amindoamine) encapsulated in silica-based yolk-shell nanostructures as an example. The CO uptake amount of Ru NPs increases sharply after H2 pyrolysis, indicating that the exposure degree of Ru NPs is increased. No aggregation of the colloidal Ru NPs occurs after H2 pyrolysis, which could be mainly assigned to the protection effect of C and N species formed on Ru NPs. The overall activity of Ru NPs in the yolk-shell nanostructure after the pyrolysis could reach as high as 20 300 mmol per mmol Ru per h in the hydrogenation of toluene, which is much higher than that of most reported Ru-based solid catalysts. It was found that the yolk-shell nanostructure could efficiently prevent the leaching of Ru NPs during the catalytic process. Ru NPs in the yolk-shell nanostructure could also catalyze the hydrogenation of benzoic acid and Levulinic acid with high activity and selectivity.
Catalytic decomposition of 2,3-dihydrobenzofuran to monomeric cyclic compounds over Pd/XCs2.5H0.5PW12O 40/OMC (ordered mesoporous carbon) (X = 10-30 wt.%) catalysts
Kim, Jeong Kwon,Park, Hai Woong,Hong, Ung Gi,Lee, Yoon Jae,Song, Ji Hwan,Song, In Kyu
, p. 68 - 72 (2014)
A series of Pd/XCs2.5H0.5PW12O 40/OMC (ordered mesoporous carbon) (X = 10, 15, 20, 25, and 30 wt.%) catalysts with different Cs2.5H0.5PW12O 40 contents (X, wt%) were prepared by a sequential incipient wetness impregnation method for use in the catalytic decomposition of 2,3-dihydrobenzofuran to monomeric cyclic compounds. 2,3-Dihydrobenzofuran was used as a lignin model compound for representing β-5 linkage of lignin. Acidity of Pd/XCs2.5H0.5PW12O40/OMC catalysts served as an important factor determining the catalytic performance in the reaction. Conversion of 2,3-dihydrobenzofuran and total yield for main products (2-ethylphenol and ethylcyclohexane) increased with increasing acidity of Pd/XCs2.5H0.5PW12O40/OMC catalysts.
Minor Modifications to the Ligands Surrounding a Ruthenium Complex Lead to Major Differences in the Way in which they Catalyse the Hydrogenation of Arenes
Dyson, Paul J.,Ellis, David J.,Laurenczy, Gábor
, p. 211 - 215 (2003)
The hydrogenation of benzene and other arenes under aqueous-organic biphasic conditions is evaluated using the ruthenium complexes Ru(η 6-C10H14)(pta)Cl2 (pta = 1,3,5-triaza-7-phosphaadamantane), Ru(η6-C10H 14)(tppts)Cl2 (tppts = tris-3-sulfonatophenylphosphine trisodium salt) and [Ru(η6-C10H14)(pta) 2Cl]+. The active catalysts formed during the hydrogenations correspond to a trinuclear cluster, a colloid and a mononuclear complex, respectively.
Catalytic decomposition of 2,3-dihydrobenzofuran to monocyclic compounds over palladium catalysts supported on sulfonated ordered mesoporous carbon
Kim, Jeong Kwon,Park, Hai Woong,Hong, Ung Gi,Lee, Yoon Jae,Song, In Kyu
, p. 9139 - 9144 (2015)
Ordered mesoporous carbon (OMC) was sulfonated at different temperature (OMC-SO3H-X, X =125, 150, 175, 200, and 225 °C) in order to provide acid sites to OMC. Palladium catalysts were then supported on OMC-SO3H-X by an incipient wetness impregnation method for use in the catalytic decomposition of 2,3-dihydrobenzofuran to monocyclic compounds. 2,3-Dihydrobenzofuran was used as a lignin model compound for representing β-5 linkage of lignin. In the catalytic decomposition of 2,3-dihydrobenzofuran over Pd/OMC-SO3H-X, ethylcyclohexane and 2-ethlyphenol were mainly produced. Conversion of 2,3-dihydrobenzofuran and total yield for main products (ethylcyclohexane and 2-ethylphenol) were closely related to the acidity of the catalysts. Conversion of 2,3-dihydrobenzofuran and total yield for main products increased with increasing acidity of Pd/OMC-SO3H-X catalysts. Among the catalysts tested, Pd/OMC-SO3H-150 with the largest acidity showed the highest conversion of 2,3-dihydrobenzofuran and the highest total yield for main products.
Supported Pt-Ni bimetallic nanoparticles catalyzed hydrodeoxygenation of dibenzofuran with high selectivity to bicyclohexane
Wu, Pengyu,Cai, Chun
, p. 234 - 238 (2021/07/10)
Catalytic hydrodeoxygenation (HDO) is one of the most effective methods to upgrade the oxygen-containing compounds derived from coal tar to valuable hydrocarbons. Herein, an efficient bimetallic catalyst Pt1Ni4/MgO was prepared and applied in the HDO of dibenzofuran (DBF). High yield (95%) of the desired product bicyclohexane (BCH) was achieved at 240 °C and 1.2 MPa of H2. Superior catalytic performance could be ascribed to the “relay catalysis” of Pt sites and Ni sites, and the reaction pathway is proposed as well. Scale-up experiment and recyclability test were also performed, which demonstrated the recyclability and promising potential application of Pt1Ni4/MgO.
Chemoselective Hydrogenation of Olefins Using a Nanostructured Nickel Catalyst
Klarner, Mara,Bieger, Sandra,Drechsler, Markus,Kempe, Rhett
supporting information, p. 2157 - 2161 (2021/05/21)
The selective hydrogenation of functionalized olefins is of great importance in the chemical and pharmaceutical industry. Here, we report on a nanostructured nickel catalyst that enables the selective hydrogenation of purely aliphatic and functionalized olefins under mild conditions. The earth-abundant metal catalyst allows the selective hydrogenation of sterically protected olefins and further tolerates functional groups such as carbonyls, esters, ethers and nitriles. The characterization of our catalyst revealed the formation of surface oxidized metallic nickel nanoparticles stabilized by a N-doped carbon layer on the active carbon support.
