Liquid-phase Oxidation Of Cyclohexane Research Articles

Kinetic features and mechanism of oxidation of cyclohexene in the presence of heterogenized Co(II) on the surface of polyethylene

1. The catalyst prepared by attachment of Co(II) ions on granules of the graft copolymer of polyethylene with acrylic acid effectively catalyzes liquid-phase oxidation of cyclohexene, ensures chain propagation (in the initial stage of the reaction) due to activation of oxygen by Co(II) ions, and catalytic decomposition of hydroperoxide with emission of radicals into the volume. 2. Chain breaking takes place both in bimolecular recombination of alkenyl peroxide radicals in the bulk and with the participation of cobalt ions on the surface of the catalyst (linear breaking). 3. The reactions of complexing and decomposition of cyclohexenyl hydroperoxide with Co(II) and Co(III) acetylacetonates were studied. The corresponding complexing constants, initiation constants, and order of the reactions were estimated. 4. The structure of the heterogeneous catalyst was studied by IR spectroscopy. Free carboxyl groups are present on the surface near the catalytic sites, and chemisorption of hydroperoxide molecules on these groups results in a high local concentration of hydroperoxide in the region of the active sites regardless of its concentration in bulk. The constancy of the rate of initiation and the rate of oxidation of the olefin is a consequence of this.

Liquid-phase oxidation of cyclohexene under catalysis by lamellar com pounds of graphite and transition-metal chlorides

1. Lamellar compounds of graphite with Cu, Co, Mn, Fe, Ni, Mo, and Znchlorides are catalytically active in the liquid-phase oxidation of cyclohexene by molecular oxygen and in the breakdown of cyclohexyl hydroper-oxides. Appreciable quantities of cyclohexene oxide are formed in these reactions on LCG-MoCl5. 2. On the basis of the determined product compositions, and our knowledge of the kinetics of heterogeneously catalyzed liquid-phase oxidation reactions, oxidation in the presence of the LCG must proceed through a radical-chain heterogeneous-homogeneous mechanism.

Flüssigphasenoxydation von Cyclohexen in Gegenwart von Kombinationen von Verbindungen verschiedener Metalle

The Liquid Phase Oxidation of Cyclohexene in Presence of Combinations of Compounds of Different MetalsThe oxidation of cyclohexene (1) with molecular oxygen in chlorobenzene solution at 80°C has been studied using cobalt, manganese and copper compounds, respectively in combination with molybdenum complexes. The selectivity has been determined of cyclohex‐2‐en‐1‐hydroperoxide (2), epoxycyclohexane (3), cyclohex‐2‐en‐1‐ol (4), cyclohex‐2‐en‐1‐one (5), 2,3‐epoxy‐cyclohexane‐1‐ol (6) and cyclohexane‐1,2‐diol (7), formed from reacted 1. Investigation of the consecutive reactions showed that 3 and especially 4 can react in different ways and moreover 4 inhibits the oxidation of 1. From these results conclusions were drawn on the mechanism of oxidation of 1.

Inhibiting action of metal selenides in the oxidation of cyclohexene

1. 1. It was established that metal selenides (Mo, Ta, Cu) have an inhibiting effect in liquid-phase oxidation of cyclohexene, initiated by aziosobutyric acid denitrile. 2. 2. It was shown that MoSe 2 takes part in the stage of termination and in degenerate chain branching.

Heterogeneous Catalysis in the Liquid-phase Oxidation of Olefins. IV. The Activity of a Supported Vanadium or Chromium Oxide Catalyst in the Decomposition of t-Butyl Hydroperoxide

Abstract The liquid-phase decomposition of t-butyl hydroperoxide (t-BuOOH) has been carried out in benzene under an N2 atmosphere using a vanadium or chromium oxide, supported on γ-Al2O3 or SiO2 as the catalyst, for the purposeof clarifying the reaction mechanism of the cyclohexene oxidation. The decomposition of t-BuOOH on the supported oxide catalyst was a first-order reaction; the main products were t-butyl alcohol, di-t-butyl peroxide, and acetone, suggesting that t-BuOOH is decomposed homolytically on the catalyst by the Haber-Weiss mechanism. The effect of the vanadium–chromium binary system formation was small, but the interaction between metal oxides and the supports appeared to be important in the t-BuOOH decomposition. Tetrahedrally co-ordinated vanadium species were formed on SiO2 and showed the highest activity, followed by the chromium co-ordinated tetrahedrally on SiO2 or on γ-Al2O3, while an octahedrally co-ordinated vanadium or chromium showed low activity. Such order of the activity was in good agreement with that obtained in the liquid-phase oxidation of cyclohexene. We observed a relatively good correlation between the catalytic activity and the acidity of the supported binary metal oxides. The V2O5–SiO2 system showed an especially large acidity; here t-butyl alcohol was dehydrated into di-t-butyl ether and 2-methyl propene.

Regarding the Organic Acid Formed During the Liquid Phase Oxidation of Cyclohexane

Experiment on the oxidation of cyclohexane in liquid phase to produce cyclohexanone was carried out in a pilot plant. In order to adequately refine cyclohexanone and cyclohexanol, and also the byproduct, adipic acid, produced in the liquid phase oxidation of cyclohexane, the organic acids simultaneously produced were studied by paper chromatographical test.The fatty acids and dibasic acids of less than 6 carbon atoms were determined in the water and the filtrates of the oxidized products.The fatty acids obtained were: Formic acid, acetic acid, propionic acid, butyric acid, valeric acid, and caproic acid.The dibasic acids obtained were: Oxalic acid, malonic acid, succinic acid, glutaric acid, and adipic acid.

Production of Cyclohexanone by liquid Phase Oxidation of Cyclohexane

Production of Cyclohexanone by liquid Phase Oxidation of Cyclohexane

Regarding the Qualities of Cyclohexanone Produced by Liquid Phase Oxidation of Cyclohexane

The qualities of cyclohexanone and cyclohexanol, produced from cyclohexane, by method of liquid phase oxidation, were investigated by gas chromatography and ultra-violet absorption spectrography, in order to confirm whether the cyclohexanone obtained from oxidation process could be used for the production of nylon 6.Experiments were performed with both saponified and unsaponified samples and the following results were obtained:1. The gas chromatographic results of cyclohexanone and cyclohexanol produced by oxidation showed no difference from that of cyclohexanone and cyclohexanol produced from phenol.2. The data indicated by the ultra-violet absorption spectrographic test of cyclohexanone produced by oxidation proved different from that of cyclohexanone produced from phenol by 230mμ wave length.3. After saponification, or the rectification of the samples, the ultra-violet absorption spectrographic results were found to be the same.

(222)シクロヘキサンの加圧液相空気酸化に関する研究(第4報)連鎖進行期の反応機構および反応中生成する酸化妨害物質について

(222)シクロヘキサンの加圧液相空気酸化に関する研究(第4報)連鎖進行期の反応機構および反応中生成する酸化妨害物質について

(280)シクロヘキサンの液相加圧空気酸化に関する研究 (第1報) 誘導期に対する反応条件の影響

(280)シクロヘキサンの液相加圧空気酸化に関する研究 (第1報) 誘導期に対する反応条件の影響

(319)シクロヘキサンの液相加圧空気酸化に関する研究 (第2〜3報) (第3報) 酸化生成物の組成に対する反応圧および反応温度の影響

(319)シクロヘキサンの液相加圧空気酸化に関する研究 (第2〜3報) (第3報) 酸化生成物の組成に対する反応圧および反応温度の影響

(318)シクロヘキサンの液相加圧空気酸化に関する研究 (第2〜3報) (第2報) 定常連鎖進行期の酸素吸収速度, および過酸化物の生成について

(318)シクロヘキサンの液相加圧空気酸化に関する研究 (第2〜3報) (第2報) 定常連鎖進行期の酸素吸収速度, および過酸化物の生成について