5048-19-1Relevant academic research and scientific papers
Hierarchical silicalite-1 octahedra comprising highly-branched orthogonally-stacked nanoplates as efficient catalysts for vapor-phase Beckmann rearrangement
Chang, Albert,Hsiao, Hsu-Ming,Chen, Tsai-Hsiu,Chu, Ming-Wen,Yang, Chia-Min
supporting information, p. 11939 - 11942 (2016/10/09)
A triblock structure-directing agent was designed to synthesize hierarchical silicalite-1 octahedra comprising highly-branched, orthogonally-stacked and self-pillared nanoplates that exhibited excellent and stable activity for the vapor-phase Beckmann rearrangement of cyclic oximes and high lactam selectivity.
Vapor-phase Beckmann rearrangement of cyclohexanone oxime over halide cluster catalysts
Nagashima, Sayoko,Kamiguchi, Satoshi,Ohguchi, Satoshi,Chihara, Teiji
experimental part, p. 135 - 138 (2012/02/03)
When a silica gel-supported tungsten halide cluster with an octahedral metal framework, (H3O)2[(W6Cl 8)Cl6]·6H2O/SiO2, is treated in a helium stream in the temperature range 250-350 °C, catalytic activity for the Beckmann rearrangement of cyclohexanone oxime develops. Niobium and tantalum clusters with the same metal framework also catalyze the reaction. Cyclopentanone oxime and acetone oxime also undergo Beckmann rearrangements over the tungsten cluster. The weak Br?nsted acidity (H0 ≈ +1.5) of the hydroxo ligand, which is developed on the activated cluster, is favorable for the rearrangement.
Catalytic properties of WOx/SBA-15 for vapor-phase Beckmann rearrangement of cyclohexanone oxime
Bordoloi, Ankur,Halligudi
experimental part, p. 141 - 147 (2010/09/05)
WOx/SBA-15 nanocomposite materials with different WOx loadings were prepared by one step hydrothermal synthesis and used in the vapor-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam. The catalysts were thoroughly characterized by X-ray diffraction (XRD), sorption analysis, energy dispersive X-ray analysis (EDAX) and Raman spectroscopy. The acidities of the catalysts were estimated by ammonia temperature programmed desorption (NH3-TPD) and Fourier transform infrared studies of adsorbed pyridine (pyridine-FTIR). The optimum temperature for the Beckmann rearrangement was 350 °C. Using WOx/SBA-15(20) under the vapor-phase reaction conditions [temperature = 350 °C, WHSV = 0.6 h-1, oxime concentration = 2.5% (w/w) in MeOH] gave 79% cyclohexanone oxime conversion with 93%, ε-caprolactam selectivity. The ε-caprolactam selectivity was found to be dependent on temperature and space velocity. A correlation has been made between the rearrangement activity and acidity and the structural properties of the catalysts.
Gas-phase catalytic Beckmann rearrangement over crystalline BPO4 of dehydration ability
Tsuji, Hideto,Setoyama, Tohru
, p. 1232 - 1233 (2007/10/03)
The crystalline BPO4 with a P/B ratio around 1.5 prepared by dehydration of boric and phosphoric acid was found to be an effective heterogeneous catalyst for the gas-phase Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam. Copyright
Synthesis of ε-caprolactam from cyclohexanone oxime using zeolites Hβ, HZSM-5, and alumina pillared montmorillonite
Ouyang, Kuang-Hao,Chen, Chih-Wei,Ko, An-Nan
, p. 137 - 144 (2007/10/03)
The Beckmann rearrangement of cyclohexanone oxime (CHO) to ε-caprolactam (ε-C) was studied in a plug flow reactor at 300-400°C under atmospheric pressure by using Hβ, ZSM-5, and alumina pillared montmorillonite. With Hβ(X)Y zeolites, raising the SiO2/Al2O3 molar ratio (X) results in the enhancement of catalyst acid strength with concomitant decrease of the total acid amount. Increasing the calcination temperature (Y) causes remarkable diminution of catalyst surface area, acid strength, and acid amount. A similar trend was found for AIPMY catalysts. In the reaction of CHO, the initial catalytic activity correlates well with the total acid amount of various catalysts except for Hβ(10)Y (Y > 600°C). The reaction proceeds on both Broensted and Lewis acid sites and the catalyst deactivation most likely occurs at the strong Broensted acid sites. The effect of solvents in the feed on the catalytic results was also investigated; it was found that polar solvents such as ethanol or n-butanol give high ε-C yield and longer catalyst lifetime. In the reaction of CHO/C2H5OH over Hβ(10)800 at 400°C and W/F 74.6 g·h/mol, the CHO conversion and ε-C yield remain 100% and 92%, respectively, for at least 20 h time-on-stream. The reaction paths and the mechanism for ε-C formation are proposed.
Vapor phase Beckmann rearrangement of cyclohexanone oxime over a novel tantalum pillared-ilerite
Ko, Younghee,Kim, Myung Hun,Kim, Sun Jin,Seo, Gon,Kim, Mi-Young,Uh, Young Sun
, p. 829 - 830 (2007/10/03)
The vapor phase Beckmann rearrangement of cyclohexanone oxime has been studied using a novel tantalum pillared-ilerite as catalyst: the cyclohexanone oxime conversion rate reaches 97.1% and the selectivity for ε- caprolactam is up to 89.1% at 350 °C.
Vapour phase Beckmann rearrangement of cyclohexanone oxime catalysed by Hβ zeolite
Dai, Lian-Xin,Hayasaka, Raita,Iwaki, Yoshihide,Koyano, Keiko A.,Tatsumi, Takashi
, p. 1071 - 1072 (2007/10/03)
When hexan-1-ol was used as the diluent in the vapour phase Beckmann rearrangement of cyclohexanone oxime, Hβ zeolite gave 100% conversion of the oxime with ε-caprolactam selectivity close to 96%.
Vapor-Phase Beckmann Rearrangement of Cyclohexanone Oxime over an HY Zeolite Catalyst Calcined at High Temperature
Sato, Satoshi,Takematsu, Kiyotaka,Sodesawa, Toshiaki,Nozaki, Fumio
, p. 1486 - 1490 (2007/10/02)
The vapor-phase Beckmann rearrangement of cyclohexanone oxime over an HY zeolite calcined at high temperature was investigated.Cyclohexanone oxime was rearranged into ε-caprolactam with high conversion at 573 K over an HY zeolite calcined at 873 K.The activity decay was slight, while oxime conversion over an HY zeolite calcined at 773 K steeply decreased during the initial stage of the reaction.The catalytic activity for the rearrangement was not correlated with the physical properties of a fresh catalyst, but with those of a used one, especially regarding their porosity and acidity.It was also found that the produced ε-caprolactam was tightly adsorbed on strong acid sites, filling the micropores of the zeolite during the initial stages of the reaction, and that a large portion of the catalytic reaction proceeded mainly on weak acids sites located in a region near to the external surface of the zeolite.
Electrochemical carboxylation of terminal alkynes catalyzed by nickel complexes: unusual regioselectivity
Dunach, Elisabet,Perichon, Jacques
, p. 239 - 246 (2007/10/02)
The electrochemical reduction of the nickel(II) complex Ni(bipy)3(BF4)2 yields an active catalyst for the regioselective functionalization of the 2-position of terminal alkynes with carbon dioxide.A series of α-substituted acrylic acids have been obtained with selectivities of 65-90percent and fair overall yields.
VAPOR-PHASE BECKMANN REARRANGEMENT OF CYCLOHEXANONE OXIME OVER SILICA-BORIA CATALYST PREPARED BY CHEMICAL VAPOR DEPOSITION METHOD
Sato, Satoshi,Sakurai, Hiroaki,Urabe, Kazuo,Izumi, Yusuke
, p. 277 - 278 (2007/10/02)
Cyclohexanone oxime was converted to ε-caprolactam in a high yield of 93percent at 250 deg over a silica-supported boron oxide catalyst which was prepared by means of chemical vapor deposition.This catalyst was much more efficient than silica-boria and alumina-boria which were obtained by the usual impregnation method.
