- Rate enhancing of carbon dioxide in the reaction of acetonitrile with methanol to acrylonitrile over magnesium oxide catalyst
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Carbon dioxide greatly enhanced the formation of acrylonitrile in the gas-phase reaction of acetonitrile with methanol over magnesium oxide catalyst.The reaction in the presence of carbon dioxide was accompanied by the reaction of methanol with carbon dioxide to give carbon monoxide and water.An adsorbed carbon dioxide species on the basic surface of magnesium oxide seems to afford an active methanol-derived species for the reaction with acetonitrile.
- Lin, Yi Wen,Ishi, Makoto,Ueda, Wataru,Morikawa, Yutaka
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- Synthesis of MoVNbTe(Sb)Ox composite oxide catalysts via reduction of polyoxometalates in an aqueous medium
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The synthesis of MoVNbTe(Sb)Ox composite oxide catalysts based on the self-organization of polyoxometalates (POMs) was investigated. The catalysts which were synthesized via reduction of POMs by using reducing agents under mild conditions and/followed by calcination in an O2-excluded atmosphere which superior performance for propane (amm)oxidation. It was suggested that the metastable phase formed at an elevated temperature with a specific oxidation state corresponds to the catalytic activity. Copyright
- Tsuji, Hideto,Koyasu, Yukio
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- Enantioselective Folding at the Cyclodextrin Surface
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Spectroscopic and kinetic studies of β-cyclodextrin-linked L- and D-phenylalanine cyanoethyl esters in aqueous solution reveal an unusual intramolecular complexation mode where the hydrophobic portion of the amino acid resides outside the host cavity; L- and D-derivatives show different binding geometries and energies.
- Eliseev, Alexey V.,Iacobucci, Guillermo A.,Khanjin, Nikolai A.,Menger, F. M.
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- Study of the local structure and oxidation state of iron in complex oxide catalysts for propylene ammoxidation
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Iron molybdate plays a crucial role in the complex oxide catalysts used for selective oxidation and ammoxidation of hydrocarbons but its structural and electronic properties and their changes in the process of the reaction are poorly understood. A combination of Raman, X-ray absorption, and UV-visible spectroscopy was applied to investigate a commercial catalyst as a function of the reaction time. The results show that an iron-containing compound exists predominantly as ferric molybdate in the fresh catalyst, which is reduced progressively in the process of reaction, forming predominantly ferrous molybdate. The irreversible transformation from Fe2(MoO 4)3 to FeMoO4 was accompanied by formation of a small amount of Fe2O3. These two processes observed in our experiment shed light on the deactivation mechanism of this complex catalyst because they have a negative effect on the selectivity and activity. Specifically, they are responsible for the deterioration of the redox couple, blocking the transmission of lattice oxygen, and irreversibly changing the catalyst structure. Based on the results of the combined techniques, a refined procedure has been proposed to develop a more stable and efficient selective oxidation catalyst.
- Wu, Li-Bin,Wu, Liang-Hua,Yang, Wei-Min,Frenkel, Anatoly I.
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- PYROLYSIS OF PROPIONITRILE AND THE RESONANCE STABILISATION ENERGY OF THE CYANOMETHYL RADICAL
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The pyrolysis of propionitrile has been studied at seven temperatures over the range 789-850 K and pressures between 10 and 100 Torr.Under these conditions the principal reaction products which are formed by essentially homogeneous processes are hydrogen, hydrogen cyanide, methane, ethane, ethene, acetonitrile and acrylonitrile.For short reaction times (A free radical chain mechanism has been proposed which accounts for all the above products.The chain initiating step is the reaction .Measurements of the rate of formation of methane in the subsequent reaction yield the rate expression where Θ = 2.303 RT/cal mol-1.The activation energy leads to D(H3C-CH3CN) = 80.4 +/- 1 kcal mol-1 and a resonance energy of 5.4 +/- 1.4 kcal mol-1 for the cyanomethyl radical.
- Trenwith, Antony B.
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- Ammoxidation of allyl alcohol-a sustainable route to acrylonitrile
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The ammoxidation of allyl alcohol was demonstrated over antimony-iron oxide catalysts with a Sb/Fe ratio of 0.6 and 1. Both catalysts showed high performance with 83 and 84% yield of acrylonitrile, respectively, whereby the main difference was found in the initial performance. This was ascribed to the in-operando formation of the SbFeO4 mixed oxide on the catalyst surface under reaction conditions, as proven by XPS analysis.
- Guillon, Cyrille,Liebig, Carsten,Paul, Sebastien,Mamede, Anne-Sophie,Hoelderich, Wolfgang F.,Dumeignil, Franck,Katryniok, Benjamin
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- Catalytic properties of nitrided V/Al/O-mixed oxides in the ammoxidation of propane and new efficient preparation method for the catalysts
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V/Al/O oxides have been prepared and tested as catalysts for the ammoxidation of propane into acrilonitrile at 500 °C. The high efficiency of these catalysts, which were partially nitrided under catalytic reaction conditions, is confirmed. The best catalysts characterized by a V/Al ratio around 0.30, exhibited selectivity to acrilonitrile of 51% at 58% conversion. Testing at low conversion showed that propene was the main primary product from propane ammoxidation and that the reaction pathway on these catalysts was similar to that on other efficient catalytic systems. A new method of synthesis based upon the decomposition at low temperature of a mixed ammonium aluminum-vanadium oxalate was developed. It leads to highly active catalysts, which displayed increased selectivity to acrylonitrile. The gain in activity and selectivity was attributed to a better dispersion of vanadium with a higher concentration of isolated vanadium species in the bulk and presumably at the surface of the catalysts.
- Bilde,Janke,Brückner,Millet
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- Regioselective synthesis of 1,2,4-triazol-3(2H)-ones and their 3(2H)-thiones: Kinetic studies and selective pyrolytic deprotection
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Selective pyrolytic deprotection of 2-ethyl and 2-cyanoethyl-4-arylidenimino-1,2,4-triazol-3(2H)-ones and their 3(2H)-thiones was studied by flash vacuum pyrolysis. This study is useful in regioselective synthesis of 2-and 4-substituted 1,2,4-triazoles of potential biological applications. The kinetic results and product analysis lend support to a reaction pathway involving a six-membered transition state.
- Al-Awadi, Nouria A.,Ibrahim, Yehia A.,Kaul, Kamini,Dib, Hicham
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- Highly active and selective supported bulk nanostructured MoVNbTeO catalysts for the propane ammoxidation process
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We report a methodology to prepare nanoscaled supported-bulk MoVNbTeO catalysts in which the phases required to obtain an active and selective catalysts are nanoscaled on the surface of a support. Thus, a more economic catalytic material with improved mechanical properties can be obtained. The effect of vanadium content and atmosphere of calcination on the catalytic performance are discussed, and the results of the supported-catalysts are compared with those of bulk catalytic samples, which have been prepared as reference. The best supported catalyst afford ca. 50% acrylonitrile yield with 80% propane conversion at 450 °C. The activity per gram of MoVNbTeO increases fourfold upon stabilization of its nanoparticles.
- Lopez-Medina, R.,Rojas, E.,Banares, M. A.,Guerrero-Perez, M. O.
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- Role of Promoters on the Acrolein Ammoxidation Performances of BiMoOx
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Ammoxidation of acrolein to acrylonitrile was studied using multicomponent (MC) BiMoOx catalysts in the presence of ammonia and oxygen. The MC catalysts containing bivalent and trivalent metal promoters were found to be highly active and selective to acrylonitrile. The corresponding MC catalysts were characterized by X-ray diffraction, nitrogen physisorption, X-ray photoelectron spectroscopy, ICP-MS and UV-visible diffuse reflectance spectroscopy. It was observed that, among the bivalent cations, the catalysts containing both Co-Ni showed superior performances due to the presence of the metastable β-CoxNi1-xMoO4 phase. The presence of a trivalent cation, and especially of iron, promoted the formation of both the γ-Bi2MoO6 active phase and the active β-phase of bivalent metal molybdate. Further, optimization of the reaction conditions enabled the achievement of a 59 % acrylonitrile yield.
- Ghalwadkar, Ajay,Katryniok, Benjamin,Paul, Sébastien,Mamede, Anne-Sophie,Dumeignil, Franck
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- Kinetics and mechanism of liquid-phase thermal decomposition of β-cyanoethyl-N-nitramines
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Termal decomposition of β-cyanoethyl-N-nitramine in melt is preceded by protonation of the amino nitrogen atom and is accompanied by evolution of nitrogen(I) oxide with formation of acrylonitrile. Thermal decomposition of bis(β-cyanoethyl)-N-nitramine under similar conditions follows a radical mechanism with initial dissociation of the N-N bond. The same mechanism is operative in thermal decomposition of both N-nitramines in a dilute dibutyl phthalate solution.
- Stepanov,Astakhov,Kruglyakova,Pekhotin
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- Propane Versus Ethane Ammoxidation on Mixed Oxide Catalytic Systems: Influence of the Alkane Structure
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Abstract: Catalysts from three different catalytic systems, Ni–Nb–O, Mo–V–Nb–Te–O and Sb–V–O, have been prepared, characterized, and tested during both ethane and propane ammoxidation reactions, in order to obtain acetonitrile and acrylonitrile, respectively. The catalytic results show that Mo–V–Nb–Te–O and Sb–V–O catalyze propane ammoxidation but are inactive for ethane ammoxidation whereas Ni–Nb–O catalysts catalyze both, ethane and propane ammoxidation. The activity results, and the characterization of fresh and used catalysts along with some data from previous studies, indicate that the ammoxidation reaction mechanism that occurs in these catalytic systems is different. In the case of Mo–V–Nb–Te–O and Sb–V–O, two active sites appear to be involved. In the case of Ni–Nb–O catalysts, only one site seems to be involved, which underlines that the mechanism is different and take place via a different intermediate. These catalysts activate the methyl groups in ethane, on the contrary, neither ethane nor ethylene appear to adsorb on the Mo–V–Nb–Te–O and Sb–V–O active sites. Graphical Abstract: [Figure not available: see fulltext.]
- Guerrero-Pérez, M. Olga,Rojas-García, Elizabeth,López-Medina, Ricardo,Ba?ares, Miguel A.
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- Kinetics of Pyrolysis of the Isomeric Butenenitriles and Kinetic Modeling
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Kinetics of pyrolysis of the butenenitrile isomers, cis- and trans-crotonitrile and allyl cyanide, have been studied dilute in argon in a single-pulse shock tube over the temperature range of 1200-1500 K at uniform gas residence times behind the reflected shock of between 650 and 750 μs and at pressures between 18 and 20 atm.Thermal decomposition was preceded by isomerization of the butenenitriles whose rates are coupled with the rates of thermal decomposition.The decomposition was found to follow a free-radical mechanism, with the major chain involving propagation reactions of the cyanomethyl radical to produce acetonitrile and acetylene.Other routes important to the mechanism involve hydrogen atom addition to the butenenitriles.HCN principally arises from this route.A detailed kinetic reaction model is presented to model the experimental reactants and products profiles as a function of temperature.From the modeling and experiment, the following initiation rate constants have been obtained: trans-CH3CH=CHCN -> CH3 + HC=CHCN (k-11 = 1017.45 exp(-96.5/RT) s-1), cis-CH3CH=CHCN -> CH3 + HC=CHCN (k-12 = 1017.53 exp(-98.5/RT) s-1), CH2=CHCH2CN -> H2C=CH + CH2CN (k-13 = 1015.53 exp(-82.6/RT) s-1), where the activation energies are in kcal mol-1.
- Doughty, Alan,Mackie, John C.
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- High temperature pretreatment of Fe-silicalite for the ammoxidation of propane
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Fe-silicalite with low concentration of iron was used in the study of the activation by high temperature nitridation (in the temperature range from 540 °C to 700 °C). Nitrided materials were characterized by means of FTIR and UV-Vis spectroscopy. It was f
- Raabová, Kate?ina,Bulánek, Roman,Bad'Urová, Eva
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- Effects of Polar β Substituents in the Gas-Phase Pyrolysis of Ethyl Acetate Esters
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The rates of the gas phase pyrolysis of six β-substituted ethyl acetates were studied in a static system over the temperature range 319-450 deg C and the pressure range 63-207 mmHg.In seasoned vessels the reactions are homogenous, follow a first-order rate law, and are unimolecular.The temperature dependence of the rate constants is given by the following Arrhenius equations for the compounds indicated: 2-(dimethylamino)ethyl acetate, log k(s-1) = (13.90 +/- 0.30) - (220.4 +/- 3.8) kJ*mol-1 (2.303RT)-1; 2-methoxyethyl acetate, log k(s-1) = (12.04 +/- 0.24) -(203.7 +/- 2.9) kJ*mol1- (2.303RT)-1; 2-(methylthio)ethyl acetae, log k(s-1 = (11.27 +/- 0.39) - (179.0 +/- 4.6) kJ*mol-1 (2.303RT)-1; 2-chloroethyl acetate, log k(s-1) = (12.14 +/- 0.66) - (202.0 +/- 8.4)kJ*mol-1 (2.303RT)-1; 2-fluoroethyl acetate, log k(s-1) = (12.68 +/- 0.60) - (211.2 +/- 7.1) kJ*mol-1 (2.303RT)-1; 2-cyanoethylacetate, Log k(s-1) = (11.51 +/- 0.13) - (171.9 +/- 1.7) kJ*mol-1 (2.303RT)-1.The effect of substituents in the gas-phase elimination of β-substituted ethyl acetates may be grouped in three types.The linear correlation of several -I electron-withdrawing groups along strong ? bonds is presented and discussed.A small amount of anchimeric assistance is proposed in the pyrolysis of the 2-(methyltio)ethyl acetate.The experimental data are consistent with the transition state where the Cα-O bond polarization is the rate-determining process.
- Chuchani, Gabriel,Martin, Ignacio,Hernandez, Jose A. A.,Rotinov, Alexandra,Fraile, German,Bigley, David B.
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- Pyrolysis and Photolysis Processes of Pyran and Thiopyran Derivatives
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Pyrolysis and photolysis of 2-amino-3,5-dicyano-6-phenyl-4H-pyran (1) afford HNCO, acrylonitrile, cinnamonitrile, and 2-hydroxy-3,5-dicyano-6-phenylpyridine. Pyrolysis of 2-carboxyimino-3,5-dicyano-6-phenyl-4H-pyran (2) gives HCN, acrylonitrile, cinnamonitrile and 2-hydroxy-3,5-dicyano-6-phenylpyridine. Furthermore, both pyrolysis and photolysis of 2,6-diamino-3,5-dicyanothiopyran (3a) gives rise to HNCS, acrylonitrile and 6-amino-3,5-dicyano-6-mercaptopyridin. Moreover, comparative studies of pyrolysis and photolysis of 2,6-dicyano-4-arylthiopyran derivatives 3b-d revealed similar results. The similarity of products obtained from pyrolysis and photolysis and the mechanistic implications of these data are discussed.
- Atalla,Hussein,Badr
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- Tetrakis(2-cyanoethoxy)borate - An alternative to tetracyanidoborate-based ionic liquids
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This study examines the synthesis and properties of salts of the new tetrahedral [B(O-C2H4-CN)4]- anion, which can be synthesized by the reaction of tetrahedral NaBH4 and HO-C2H4
- Harloff, Joerg,Karsch, Markus,Lund, Henrik,Schulz, Axel,Villinger, Alexander
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- Influence of alumina precursor on the physico-chemical properties of V-Sb-P-W/Al2O3 catalyst studied for the ammoxidation of propane
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Influence of alumina precursor on active phase formation in V1.0-Sb3.5-P0.5-W1.0/50% Al2O3 catalyst was studied for the ammoxidation of propane in the temperature range of 490-530°C at W/F
- Pasupulety, Nagaraju,Driss, Hafedh,Zaman, Sharif F.,Alhamed, Yahia Abobakor,Alzahrani, Abdulrahim Ahmed,Daous, Muhammad A.,Petrov, Lachezar
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- Operando raman study of alumina-supported Sb-V-O catalyst during propane ammoxidation to acrylonitrile with on-line activity measurement
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Operando Raman spectra during propane ammoxidation show partially reversible structural transformations of the active phases as a function of reaction environment.
- Guerrero-Perez,Banares
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- Ammoxidation of acrolein to acrylonitrile over bismuth molybdate catalysts
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The present work deals with the potentially significant process converting acrolein of green origin to acrylonitrile using mesoporous bismuth molybdate catalysts. The ammoxidation catalysts were characterized by N2 physisorption, X-ray diffraction, and catalytic tests under various conditions at different temperatures, contact times, and reactant molar ratios. The results indicated a catalytic activity proportional to specific surface area, which depends on bismuth molybdate phases, and concentration of oxygen in the gas feed. The selectivity of the catalysts only depends on reaction temperature. ACN selectivity obtained at 350-400 °C was 100% and reduced to 97% at 450 °C.
- Thanh-Binh, Nguyen,Dubois, Jean-Luc,Kaliaguine, Serge
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- The Mutual Promotion Effect of Molybdates in Multicomponent Molybdate Catalysts
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Multicomponent molybdate catalysts (e.g. of the composition Bi2Fe1.5Co7Cr10Mo19Oy) are produced by coprecipitation, drying and calcination.These catalysts exhibit high activity and selectivity in the ammoxidation of propene to acrylonitrile.The individual molybdates (Co-, Fe- and Cr-molybdate) exhibit no selectivity in the ammoxidation of propene.Therefore a mutual promotion effect of these molybdates exists.The cause of the promotion effect is the formation of the active and selective phase from the β-phase of Co-molybdate by exchange of protons with ions of Fe3+ and Cr3+ from the molybdates of Fe and Cr.The structure of this catalytic active and selective phase is similar to the structure of the β-phase of Co-molybdate.
- Kripylo, P.,Hohlstamm, I.,Koppe, J.,Kraak, P.,Rapthel, I.,Hofmann, A.
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- Kinetics and mechanism of thermal gas-phase elimination of β-substituted carboxylic acids
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3-Phenoxypropanoic acid (1), 3-(phenylthio)propanoic acid (2), and 4-phenylbutanoic acid (3) were pyrolysed between 520 and 682 K. Analysis of the pyrolysates showed the elimination products to be acrylic acid and the corresponding arene. Pyrolysis of ethyl 3-phenoxypropanoate (4) and its methyl analogue (5), ethyl 3-(phenylthio)propanoate (6) and its methyl counterpart (7), and 3-phenoxypropane nitrile (8) were also investigated between 617 and 737 K. The thermal gas-phase elimination kinetics and product analysis are compatible with a thermal retro-Michael reaction pathway involving a four-membered cyclic transition state.
- Al-Awadi,Abdallah,Dib,Ibrahim,Al-Awadi,El-Dusouqui
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- Looking for heteroaromatic rings and related isomers as interstellar candidates
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Finding complex organic molecules in the interstellar medium (ISM) is a major concern for understanding the possible role of interstellar organic chemistry in the synthesis of prebiotic species. The present interdisciplinary report is a prospective study aimed at helping detection of heteroaromatic compounds or at least of some of their isomers in the ISM. The thermodynamic stabilities of the C4H5N, C4H4O, C4H4S families were calculated using density functional theory (DFT). It was found that pyrrole, furan and thiophene are unambiguously the most stable isomers at the 10-50 K temperatures of the ISM. Several of the less stable isomers were synthesized and flash vacuum thermolysis experiments were performed on these species. Although the detection of pyrrole in the pyrolysis of many compounds has been reported in the literature, we observed that none of its isomers led to pyrrole in these conditions, which suggests that other formation routes are to be considered. On the other hand, these three aromatic compounds present a very high stability, few % been decomposed at 1500 K by flash vacuum thermolysis; these experiments also show a great stability of crotonitrile that is the most stable compound that can be formed in these conditions. The rotational constants, dipole moments and IR frequencies of the low-lying isomers are given to encourage laboratory experiments on these prototype molecules.
- Lattelais,Ellinger,Matrane,Guillemin
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- Ammoxidation of Propane over Antimony-Vanadium-Oxide Catalysts
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Catalysts belonging to the Sb-V-O system were prepared with various Sb/V ratios and were used for propane ammoxidation to acrylonitrile.XRD patterns of freshly prepared samples show those with excess vanadia to consist of V2O5 ans SbVO4, while SbVO4 and α-Sb2O4 are constituents in the samples with a Sb/V ratio above unity.High rate and selectivity for propylene formation at low conversion are characteristic for samples with excess vanadia and considering XRD, Raman, infrared, and XPS results, this is explained by formation of amorphous vanadia spread over the surface of SbVO4.Catalysts with both α-Sb2O4 and SbVO4 phases are the most selective for acrylonitrile formation, a function that is linked to their ability to selectively transform intermediate propylene.XPS data suggests this function to be associated with the formation of suprasurface antimony sites on SbVO4 as a results of migration of antimony from α-Sb2O4 during the catalytic process.Raman and infrared spectral features revealed that compared with SbVO4, the samples with both α-Sb2O4 and SbVO4 are more efficiently reoxidises during propane amoxidation.Rate dependences on the partial pressures of reactants over a sample with excess α-Sb2O4 show that the adsorption of propane is the rate limiting step for propylene formation, and that acrylonitrile and carbon oxides are predominantly formed from the intermediate propylene in routes comprising nonequilibrated steps.Addition of water vapour results in an increase of rate and selectivity for acrylonitrile formation.The kinetic dependences indicate that for acrylonitrile formation it is advantageous in have a feed rich in propane and to use recirculation for obtaining high productivity.
- Nilsson, Roland,Lindblad, Thomas,Andersson, Arne
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- Mechanism of Gas Phase Cyanation of Alkenes and Aromatics
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ICN was photolyzed at 254 nm in the gas phase in the presence of 15-20 torr of certain alkenes or aromatics.The products were analyzed by GC-MS.Ethene gave acrylonitrile; propene gave acrylonitrile, allyl cyanide and cis- and trans-1-cyanopropene; 2-methylpropene gave 2 cyanopropene; benzene gave benzonitrile; toluene gave benzonitrile and 2-, 3-, and 4-cyanotoluene.These products are explained by a mechanism involving attack of CN on the organic to give vibrationally excited radicals.These radicals rapidly fragment, producing the major products, or react more slowly in bimolecular processes.The relevance of these results to RF discharge chemistry is discussed.
- Henis, Neil B. H.,Miller, Larry L.
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- Structure, activity and selectivity relationships in propane ammoxidation to acrylonitrile on V-Sb oxides: Part 3 modifications during the catalytic reaction and effect of feed composition
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The change in surface reactivity up until steady-state behavior is reached in propane ammoxidation of a series of V-Sb-oxide catalysts with Sb : V ratios in the range 1-10 and prepared either by calcination or heat treatment in vacuum at 600°C is reported and analyzed in terms of the change in the structural features of the catalyst determined as a function of the time on stream by IR spectroscopy, X-ray diffraction and chemical analysis data. The results indicate that during the catalytic reaction, V5+ oxide when present, quickly reduces forming a V4+O2/VSbO4 solid solution with an increase in the selectivity to propene, but not to acrylonitrile. An increase in the selectivity and productivity to acrylonitrile occurs when an Sb-rich approximate VSbO4 phase forms ('VSbO4'). This phase, however, is partially metastable, decomposing to 'VSbO4' + Sb2O4 when Sb5+ ions are reduced and not rapidly reoxidized. V5+ ions on the surface of the rutile phase stabilize the Sb-rich 'VSbO4' phase, and catalyze the reoxidation of Sb3+. This side oxidation of ammonia to nitrogen competes for the reduction of these V5+ ions and influences the above redox and solid-state reactions. Therefore, a considerable dependence of the surface reactivity on the feed was observed. The optimal catalytic behavior determined for the series of catalysts studied was found to depend on the feed composition indicating that in the analysis of the structure, activity and selectivity relationships in propane ammoxidation the concentration of reactants in the feed plays a specific important role.
- Centi, Gabriele,Guarnieri, Francesco,Perathoner, Siglinda
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- Application of high throughput screening to heterogeneous liquid and gas phase oxidation catalysis
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The application of combinatorial methods to oxidation catalysis in the liquid and gas phases is described. New lead materials have been discovered for the selective liquid phase oxidation of alcohols to aldehydes/ketones catalyzed by vanadium supported on carbon, for the low temperature CO oxidation/ light off for cold start automotive emissions control over supported noble metals and perovskites, for volatile organic compound (VOC) removal using CoCr oxide catalysts, and for the selective gas phase oxidation of propane to acrylic acid and acrylonitrile using mixed metal oxides. Catalyst discovery libraries were screened in 96-well batch reactors, in a rapid serial scanning mass spectrometer and in a massively parallel microfluidic reactor as primary screens. Promising hits were scaled up in conventional autoclaves or in multi-channel fixed bed secondary/ tertiary screening reactors.
- Guram, Anil,Hagemeyer, Alfred,Lugmair, Claus G.,Turner, Howard W.,Volpe Jr., Anthony F.,Weinberg, W. Henry,Yaccato, Karin
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- Cobalt(II) complexes of nitrile-functionalized ionic liquids
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A series of nitrile-functionalized ionic liquids were found to exhibit temperature-dependent miscibility (thermomorphism) with the lower alcohols. Their coordinating abilities toward cobalt(II) ions were investigated through the dissolution process of cobalt(II) bis(trifluoromethylsulfonyl)-imide and were found to depend on the donor abilities of the nitrile group. The crystal structures of the cobalt(II) solvates [Co(C1C1CNPyr) 2(Tf2N)4] and [Co(C1C 2CNPyr)6][Tf2N]8, which were isolated from ionic-liquid solutions, gave an insight into the coordination chemistry of functionalized ionic liquids. Smooth layers of cobalt metal could be obtained by electrodeposition of the cobalt-containing ionic liquids.
- Nockemann, Peter,Pellens, Michael,Van Hecke, Kristof,Van Meervelt, Luc,Wouters, Johan,Thijs, Ben,Vanecht, Evert,Parac-Vogt, Tatjana N.,Mehdi, Hasan,Schaltin, Stijn,Fransaer, Jan,Zahn, Stefan,Kirchner, Barbara,Binnemans, Koen
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- Alkylating potential of α,β-unsaturated compounds
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Alkylation reactions of the nucleoside guanosine (Guo) by the α,β-unsaturated compounds (α,β-UC) acrylonitrile (AN), acrylamide (AM), acrylic acid (AA) and acrolein (AC), which can act as alkylating agents of DNA, were investigated kinetically. The following conclusions were drawn: i) The Guo alkylation mechanism by AC is different from those brought about the other α,β-UC; ii) for the first three, the following sequence of alkylating potential was found: AN > AM > AA; iii) A correlation between the chemical reactivity (alkylation rate constants) of AN, AM, and AA and their capacity to form adducts with biomarkers was found. iv) Guo alkylation reactions for AN and AM occur through Michael addition mechanisms, reversible in the first case, and irreversible in the second. The equilibrium constant for the formation of the Guo-AN adduct is Keq (37 °C) = 5 × 10-4; v) The low energy barrier (≈10 kJ mol -1) to reverse the Guo alkylation by AN reflects the easy reversibility of this reaction and its possible correction by repair mechanisms; vi) No reaction was observed for AN, AM, and AA at pH 8.0. In contrast, Guo alkylation by AC was observed under cellular pH conditions. The reaction rate constants for the formation of the α-OH-Guo adduct (the most genotoxic isomer), is 1.5-fold faster than that of γ-OH-Guo. vii) a correlation between the chemical reactivity of α,β-UC (alkylation rate constants) and mutagenicity was found.
- Manso, Jose A.,Cespedes Camacho, Isaac F.,Calle, Emilio,Casado, Julio
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- Ammoxidation of Propane on Nickel Antimonates: The Role of Vanadium as Promoter
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The catalytic behaviour of Ni-Sb mixed oxides doped by vanadium has been investigated for the ammoxidation of propane and propene to acrylonitrile. The binary nickel antimonates, with 1:1 80%) but they showed no activity in propane ammoxidation till 470°C. The activity/gram and the yield in acrylonitrile (ACN)/gram presented a maximum at Ni:Sb 1:2 due to a balance between the surface area and the doping effect of antimony. With the addition of vanadium to the Ni-Sb system, the activity and productivity of the catalysts were increased markedly, both in propane and propene ammoxidation. The optimum vanadium loading in terms of ACN yield was found for NiSb2O6 to be V:Ni 0.2:1 atomic ratio, a compromise between activity and selectivity. It was found that sites containing vanadium are involved in the selective nitrogen insertion step in propene ammoxidation, as well as in the activation of propane. The ammoxidation of propane is a cleaner reaction than the ammoxidation of propene, as smaller amounts of hydrogen cyanide (HCN) and acetonitrile (AceN) were formed for the same yield of acrylonitrile. X-ray analysis revealed the presence of NiSb2O6 and free αSb2O4 in all samples. In the Ni-Sb vanadium doped oxides the FTIR characterisation showed that up to a V:Ni ratio of 0.2, vanadium species different from V2O5, and very likely interacting with the NiSb2O6, were formed; these species are the ones involved in propane activation. With higher loadings of vanadium, V2O5 species formed which are responsible for the lowering of acrylonitrile selectivity.
- Cassidy,Pollastri,Trifiro
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- Elimination Reactions of β-Cyano Thioethers: Internal Return and the Lifetime of the Carbanion Intermediate
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The E1cB elimination reaction of the pentafluorothiophenol adduct of fumaronitrile (3) in water containing 8.3percent Me2SO shows strong buffer catalysis and primary deuterium isotope effects of kH/kD = 4-5.In contrast, hydrogen exchange of the methanethiol adduct of 3 shows little or no buffer catalysis.There is no incorporation of deuterium that gives an inverse solvent isotope effect in the buffer-catalyzed elimination of the thionitrobenzoate adduct of 3 in D2O and H2O, although thiol anion expulsion is partly rate limiting for this reaction.These observations are consistent with internal return of the abstracted proton from the protonated buffer base that is competitive with the expulsion of leaving groups with pKa > 4.The primary deuterium isotope effects for elimination catalyzed by hydroxide ion are kH/kD = 4.9 +/- 0.4, 4.2 +/- 0.1, 4.2 +/- 0.3, and 3.1 +/- 0.1 for the pentafluorothiophenol and thionitrobenzoate adducts of 3, the N-methyl-2-mercaptopyridinium ion adduct of acrylonitrile (1), and the pentafluorothiophenol adduct of chloroacrylonitrile (2), respectively.These isotope effects are significantly larger than values of kH/kD = 2.6 +/- 0.3, 2.2 +/- 0.1, and 2.1 +/- 0.1 for buffer-catalyzed elimination from the adducts of 1 and 3.They are also larger than (1) the primary isotope effects of kH/kD = 2.5 +/- 0.3, 2.3 +/- 0.2, and 2.3 +/- 0.2 for the p-nitrothiophenol adducts of 1 and 3 and the thiophenol adduct of 2 that were obtained from the biphasic kinetics for elimination of these compounds in D2O and (2) the product discrimination isotope effects of ca. 3 for the addition of thiol anions to 1 and 3.These observations are consistent with the formation of an unstable carbanion intermediate that undergoes competitive reprotonation by solvent, k-1, exchange of the abstracted proton with the bulk solvent, ks, and elimination, k2.Ratios of k-1/ks and k-1/k2 that were obtained from the results give values of k-1 ca. 1E11 s-1 and k2 = 1E10-1E13 s-1, assuming a value of ks = 1E11 s-1.Estimated pKa values in aqueous solution include 26.8 for NCCH2CH2SPh, 22.0 for NCCH(Cl)CH2SPhNO2, and 23.2 for NCCH2CH(CN)SCH3.
- Fishbein, James C.,Jencks, William P.
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- Propane ammoxidation on Bi promoted MoVTeNbOx oxide catalysts: Effect of reaction mixture composition
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MoVTeNbO catalysts were characterized with XRD, XPS, and FTIR techniques and tested in the ammoxidation of propane. Bismuth-modified MoVTeNbO catalysts showed a higher acrylonitrile yield than the base four-component system. The effect of the reaction mixture composition (C3H8, NH3 and O2) on selectivity towards different products was studied at propane conversion above 80%. The favorable effect of bismuth promoter on the selectivity towards acrylonitrile was explained by suppression of acrylonitrile transformation connected with decreasing acidity of the catalyst.
- Andrushkevich, Tamara V.,Popova, Galina Y.,Chesalov, Yuriy A.,Ischenko, Evgeniya V.,Khramov, Mikhail I.,Kaichev, Vasily V.
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- Ammoxidation of propane to acrylonitrile over silica-supported Fe-Bi nanocatalysts
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Ammoxidation of propane to acrylonitrile was examined over a Fe3BiOx/SiO2 sample prepared by thermal decarbonylation of [Et4N][Fe3(CO)10(μ3-Bi)] on the surface of mesoporous silica. Catalytic measurements performed at 500 °C showed that this sample yields 49% acrylonitrile selectivity at 36% propane conversion when a 5.5%C3H8/30%O2/11%NH3/He balance reaction mixture was used at a GHSV of 1360 h?1. HRSTEM, EDS, and XPS measurements indicate that mixed Fe3BiO6 oxide particles less than 2 nm in size were formed on the surface of this material under reaction conditions. A Fe/Bi atomic ratio in these particles is approximately 3:1 and the Fe and Bi ions both are in the +3 oxidation state. A Fe-Bi/SiO2 sample prepared by co-impregnation of individual Fe and Bi salts had very low activity and low selectivity for acrylonitrile formation from propane under similar experimental conditions due to larger sizes of particles formed under reaction conditions and enrichment of their surface with Fe.
- Adams, Richard D.,Alexeev, Oleg S.,Amiridis, Michael D.,Blom, Douglas,Elpitiya, Gaya,Khivantsev, Konstantin
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- Influence of the Bulk and Surface Properties on the Performance of Iron-Antimony Catalysts
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The modifications induced in Fe-Sb catalysts by the introduction of an excess of antimony oxide, which is needed in order to obtain highly slective catalysts in the ammonoxidation of propylene to acrylonitrile, were investigated by means of X-ray diffraction (X.r.d.), X-ray photoelectron spectroscopy (X.p.s.) and Moessbauer spectroscopy.More important than increasing the surface Sb:Fe ratio, a promoting effect by an excess of Sb was found to develop during activation through the formation of structurally distorted and defective FeSbO4, which appears to be the active phase.Fe2+ ions are thus introduced into the iron antimonate rutile structure near oxygen vacancies.These vacancies are possibly connected with the adsorption sites for the more strongly bound oxygen species that is responsible for allylic oxidation.
- Burriesci, Nicola,Garbassi, Fabio,Petrera, Michele,Petrini, Guido
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- New class of catalysts for the ammoxidation of propane to acrylonitrile over nickel-molybdenum mixed nitrides
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Nickel-molybdenum mixed nitride catalysts were first reported for the ammoxidation of propane to acrylonitrile. It was found that the mixed nitrides exhibited high activity and selectivity to acrylonitrile. The mixed nitride catalyst with 1.0 of Ni/Mo atomic ratios showed the best catalytic properties for propane ammoxidation. The highest yield of acrylonitrile was 28.5% at the propane conversion of 68.4% at 773 K. Copyright
- Zhang, Huimin,Zhao, Zhen,Xu, Chunming,Duan, Aijun
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- Crossed beam reaction of cyano radicals with hydrocarbon molecules. III. Chemical dynamics of vinylcyanide (C2H3CN;X 1A') formation from reaction of CN(X 2Σ+) with ethylene, C2H4(X 1Ag)
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The neutral-neutral reaction of the cyano radical, CN(X 2Σ+), with ethylene, C2H4(X 1Ag), has been performed in a crossed molecular beams setup at two collision energies of 15.3 and 21.0 kJ mol-1 to investigate the chemical reaction dynamics to form vinylcyanide, C2H3CN(X 1A') under single collision conditions. Time-of-flight spectra and the laboratory angular distributions of the C3H3N products have been recorded at mass-to-charge ratios 53-50. Forward-convolution fitting of the data combined with ab initio calculations show that the reaction has no entrance barrier, is indirect (complex forming reaction dynamics), and initiated by addition of CN(X 2Σ+) to the ? electron density of the olefin to give a long-lived CH2CH2CN intermediate. This collision complex fragments through a tight exit transition state located 16 kJ mol-1 above the products via H atom elimination to vinylcyanide. In a second microchannel, CH2CH2CN undergoes a 1,2 H shift to form a CH3CHCN intermediate prior to a H atom emission via a loose exit transition state located only 3 kJ mol-1 above the separated products. The experimentally observed mild sideways scattering at lower collision energy verifies the electronic structure calculations depicting a hydrogen atom loss in both exit transition states almost parallel to the total angular momentum vector J and nearly perpendicular to the C2H3CN molecular plane. Since the reaction has no entrance barrier, is exothermic, and all the involved transition states are located well below the energy of the separated reactants, assignment of the vinylcyanide reaction product soundly implies that the title reaction can form vinylcyanide, C2H3CN, as observed in the atmosphere of Saturn's moon Titan and toward and toward dark, molecular clouds holding temperatures as low as 10 KI. In strong agreement with our theoretical calculations, the formation of the C2H3NC isomer was not observed.
- Balucani, N.,Asvany, O.,Chang, A. H. H.,Lin, S. H.,Lee, Y. T.,Kaiser, R. I.,Osamura, Y.
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- XANES study of the dynamic states of V-based oxide catalysts under partial oxidation reaction conditions
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A XANES study under reaction conditions has been performed with two different V-based catalytic systems, Mo-V-Nb-Te-O and V-Sb-O. For this study, an alumina-supported nanoscaled bulk catalyst has been used. In all cases XANES determined the average vanadium oxidation state during reaction. XANES also demonstrated that the nanosized phases are more dynamic, and able to participate in the redox catalytic cycle without significant changes either in their structure or in the overall vanadium oxidation state. Such a stability is also apparent under oxidizing conditions.
- Guerrero-Pérez,López-Medina,Rojas-Garcia,Ba?ares
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- Effect of Fe, Ga, Ti and Nb substitution in ≈sbVO4 for propane ammoxidation
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Substitution in rutile-type ≈SbVO4 was made with Fe 3+ and Ga3+ replacing V3+, and Nb5+ replacing Sb5+. Moreover, preparations with Ti were synthesised where Ti4+ ions substitute for both V4+ and V 3+/Sb5+ pairs. ≈SbVO4-related phases containing Ti together with Fe and Ga were also prepared. The samples were characterised using X-ray diffraction, DRIFT and Raman spectroscopy. The characterisations show the formation of a cation deficient single rutile-type phase. Use of the samples in propane ammoxidation to produce acrylonitrile reveals, compared with the pure ≈SbVO4 phase, that Fe, Ga and Ti substitution in ≈SbVO4 results in lower activity but considerably higher selectivity to acrylonitrile at the same level of propane conversion. Niobium substitution, on the contrary, gives no improved catalytic properties. Correlations are presented between the catalytic and structural properties of the catalysts. It is demonstrated that isolation in the structure of the propane activating V-O. sites in a surrounding of nitrogen inserting Sb-sites results in improved selectivity for acrylonitrile formation.
- Wickman, Andreas,Andersson, Arne
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- THE CYANATION OF VINYL HALIDES CATALYZED BY NICKEL(0) COMPLEX GENERATED IN SITU
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Nickel(0) species generated in situ from NiBr2(PPh3)2-Zn-PPh3 catalyzed the formation of unsaturated nitriles from vinyl halides and potassium cyanide.The reaction proceeded under very mild conditions and was stereoselective.
- Sakakibara, Yasumasa,Yadani, Nobuichi,Ibuki, Ichiro,Sakai, Mutsuji,Uchino, Norito
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- PRODUCTION OF DINITRILES
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A process for producing dinitrile comprises supplying a C6 organic compound, an oxidizing agent, ammonia and a diluent to a reaction zone to produce a reaction mixture and contacting the reaction mixture in the reaction zone with a heterogeneous catalyst at a temperature from 50 to 200°C to convert at least a portion of the C6 organic compound to dinitrile and water and produce a reaction effluent. At least part of the reaction effluent is supplied to a separation system to separate at least dinitrile and unreacted ammonia from the reaction effluent and additional water is supplied to a portion of the reaction effluent prior to or during separation of unreacted ammonia from the reaction effluent.
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Paragraph 0088-0089
(2022/02/15)
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- METHOD FOR PRODUCING NITRILE
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The present invention provides a method of producing a nitrile from a primary amide, characterized in that the primary amide is subjected to a dehydration reaction in a supercritical fluid in the presence of an acid catalyst. The present invention achieves the object of reducing the corrosion of a reactor and the thermal decomposition of raw materials, as well as provides the effect of improving the reaction rate and nitrile selectivity.
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Paragraph 0080; 0090; 0093-0094
(2021/02/05)
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- PROCESS FOR PRODUCING UNSATURATED NITRILE
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A process for producing unsaturated nitrile comprising a reaction step of subjecting hydrocarbon to a vapor phase catalytic ammoxidation reaction in a fluidized bed reactor to produce the corresponding unsaturated nitrile, wherein, in the reaction step, a powder is fed to a dense zone in the fluidized bed reactor using a carrier gas, and a ratio of a linear velocity LV1 of the carrier gas at a feed opening to feed the powder to the fluidized bed reactor to a linear velocity LV2 of a gas in the dense zone (LV1/LV2) is not less than 0.01 and not more than 1200.
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Paragraph 0067-0080
(2021/07/31)
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- Facile dehydration of primary amides to nitriles catalyzed by lead salts: The anionic ligand matters
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The synthesis of nitrile under mild conditions was achieved via dehydration of primary amide using lead salts as catalyst. The reaction processes were intensified by not only adding surfactant but also continuously removing the only by-product, water from the system. Both aliphatic and aromatic nitriles can be prepared in this manner with moderate to excellent yields. The reaction mechanisms were obtained with high-level quantum chemical calculations, and the crucial role the anionic ligand plays in the transformations were revealed.
- Ruan, Shixiang,Ruan, Jiancheng,Chen, Xinzhi,Zhou, Shaodong
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- PROCESSES FOR STABILIZING ANTIMONY CATALYSTS
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The present disclosure relates to a process for stabilizing an antimony ammoxidation catalyst in an ammoxidation process. The process may comprise providing an antimony ammoxidation catalyst to a reactor; reacting propylene with ammonia and oxygen in the fluidized bed reactor in the presence of the antimony ammoxidation catalyst to form a crude acrylonitrile product; and adding an effective amount of an antimony-containing compound to the antimony ammoxidation catalyst to maintain catalyst conversion and selectivity; wherein the antimony-containing compound has a melting point less than 375°C. The present disclosure also relates to catalyst compositions and additional processes using the antimony ammoxidation catalyst stabilized by an antimony-containing compound.
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Paragraph 0101-0104
(2020/09/08)
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- Method for producing acrylonitrile
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PROBLEM TO BE SOLVED: To provide a method for producing acrylonitrile capable of both improving a yield by minimizing the fluctuation of the catalytic activity and reducing a yield of acrolein. SOLUTION: There is provided a method for producing a corresponding acrylonitrile by subjecting a hydrocarbon to a vapor phase contact ammoxidation reaction in the presence of a metal oxide catalyst in a fluid bed reactor, which comprises a step of extracting a catalyst during reaction from the fluid bed reactor and a step of adding an unreacted catalyst into the fluid bed reactor, wherein when the extraction amount of the catalyst during reaction extracted from the fluid bed reactor is defined as X kg based on 1 ton of the production amount of acrylonitrile and the amount scattered to the outside from the fluid bed reactor is defined as Y kg, the following expressions (1) and (2) are satisfied, X>0 (1) and 0.1≤X+Y≤1.5 (2) and when the amount of the unreacted catalyst added in a reactor is defined a Z kg based on 1 ton of the production amount of acrylonitrile, the following expression (3) is satisfied, 0.3≤Z/(X+Y)≤2.5 (3). SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
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Paragraph 0058-0062
(2021/01/15)
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- INTEGRATED METHODS AND SYSTEMS FOR PRODUCING AMIDE AND NITRILE COMPOUNDS
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Provided herein are integrated methods and systems for the production of acrylamide and acrylonitrile compounds and other compounds from at least beta-lactones and/or beta-hydroxy amides.
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Paragraph 00093; 00095-00096; 00098
(2020/09/30)
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- An Air-Stable N-Heterocyclic [PSiP] Pincer Iron Hydride and an Analogous Nitrogen Iron Hydride: Synthesis and Catalytic Dehydration of Primary Amides to Nitriles
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An air-stable N-heterocyclic PSiP pincer iron hydride FeH(PMe3)2(SiPh(NCH2PPh2)2C6H4) (4) was synthesized by Si-H activation of a Ph-substituted [PSiP] pincer ligand. The analogous strong electron-donating iPr-substituted [PSiP] pincer ligand was prepared and introduced into iron complex to give an iron nitrogen complex FeH(N2)(PMe3)(SiPh(NCH2PiPr2)2C6H4) (6). Both 4 and 6 showed similar high efficiency for catalytic dehydration of primary amides to nitriles. Air-stable iron hydride 4 was the best catalyst for its stabilization and convenient preparation. A diverse range of cyano compounds including aromatic and aliphatic species was obtained in moderate to excellent yields. A plausible catalytic reaction mechanism was proposed.
- Fenske, Dieter,Fuhr, Olaf,Li, Xiaoyan,Sun, Hongjian,Wang, Yajie,Xie, Shangqing,Zhang, Hua
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- PROCESS FOR PRODUCING METHACRYLIC ACID OR METHACRYLIC ACID ESTERS
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The present invention relates to a process for producing methacrylic acid or methacrylic acid esters. The present invention is directed to a new process for the production of methacrylic acid or alkyl methacrylate starting from Acrolein, which is available from glycerol or propane.
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(2020/03/02)
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- Acrylonitrile Derivatives from Epoxide and Carbon Monoxide Reagents
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The present invention is directed to reactor systems and processes for producing acrylonitrile and acrylonitrile derivatives. In preferred embodiments of the present invention, the processes comprise the following steps: introducing an epoxide reagent and carbon monoxide reagent to at least one reaction vessel through at least one feed stream inlet; contacting the epoxide reagent and carbon monoxide reagent with a carbonylation catalyst to produce a beta-lactone intermediate; polymerizing the beta-lactone intermediate with an initiator in the presence of a metal cation to produce a polylactone product; heating the polylactone product under thermolysis conditions to produce an organic acid product; optionally esterifying the organic acid product to produce one or more ester products; and reacting the organic acid product and/or ester product with an ammonia reagent under ammoxidation conditions to produce an acrylonitrile product.
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Paragraph 0276
(2019/01/15)
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- METHOD FOR PRODUCING (METH)ACRYLONITRILE
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PROBLEM TO BE SOLVED: To provide a method for producing (meth)acrylonitrile by using a fluidized bed reactor, which prevents breakage of the fluidized bed reactor and enables stable (meth)acrylonitrile production for a long period of time. SOLUTION: Provided is a method for producing (meth)acrylonitrile by using a fluidized bed reactor which comprises a fluidized bed reactor 2, a heat exchanger 3 connected to the fluidized bed reactor through a reaction gas derivation pipe 4, and a rapid cooling tower 5 connected to the heat exchanger and having circulation lines 5B and 5C, comprising the steps of: introducing a raw material gas into the fluidized bed reactor and carrying out an ammoxidation reaction in the presence of a catalyst to obtain a reaction gas; introducing powder into the reaction gas derivation pipe and delivering the powder and the reaction gas from the heat exchanger while washing the heat exchanger; and introducing the powder and the reaction gas derived from the heat exchanger into the rapid cooling tower, cooling and washing the reaction gas, and removing the powder, where the powder is water-soluble and a pH of an aqueous solution thereof is 5.5 or more. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2019,JPOandINPIT
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Paragraph 0055-0057
(2019/06/25)
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- SYNTHETIC METHODS FOR THE PREPARATION OF PROPYLENE AMMOXIDATION CATALYSTS
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The present disclosure relates generally to catalyst materials and processes for making and using them. More particularly, the present disclosure relates to molybdenum, bismuth and iron-containing metal oxide catalyst materials useful, for example, in the partial oxidation or ammoxidation of propylene or isobutylene, processes for making them, and processes for making acrolein, methacrolein, acrylonitrile, and methacrylonitrile using such catalysts.
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Paragraph 0109-0123
(2018/08/25)
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- Method for producing oxide catalyst, and method for producing unsaturated nitrile
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The present invention provides a method for producing an oxide catalyst comprising Mo, V, Sb, and Nb for use in a gas-phase catalytic oxidation reaction or a gas-phase catalytic ammoxidation reaction of propane or isobutane, the method comprising: a preparation step of preparing a first aqueous mixed solution containing Mo, V, and Sb; a mixing step of mixing the first aqueous mixed solution with a support raw material comprising silica sol, and a Nb raw material to obtain a second aqueous mixed solution; a drying step of drying the second aqueous mixed solution to obtain a dry powder; and a calcination step of calcining the dry powder to obtain the oxide catalyst, wherein the support raw material comprises 25% by mass or more, based on SiO2, of the silica sol having an average primary particle size of 3.0 nm or larger and smaller than 11 nm based on a total amount of the support raw material, and the silica sol comprises 55% or more of silica sol particles having a primary particle size of smaller than 11 nm.
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Page/Page column 19;
(2018/05/04)
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- Method for producing an unsaturated nitrile (by machine translation)
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Using a fluidized bed reactor, in the presence of a catalyst, a hydrocarbon vapor phase contact oxidation reaction by subjecting the reaction process has produced the corresponding unsaturated nitrile, In the reaction process, the upper end of the internal space from the upper space of the upper end of the cyclone inlet occupying the space, lower than the upper end of the lower space of the cyclone inlet is divided into two spaces when the dispersion plate to occupy a space 2, in the presence of a catalyst in the presence of a catalyst amount of the upper space to the lower space ratio, is 0.05 - 0.45, production of unsaturated nitrile. (by machine translation)
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Paragraph 0042-0054; 0063
(2019/01/06)
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- Synthesis of silyl iron hydride: Via Si-H activation and its dual catalytic application in the hydrosilylation of carbonyl compounds and dehydration of benzamides
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The hydrido silyl iron complex (o-Ph2PC6H4SiMe2)Fe(PMe3)3H (2) was obtained via the activation of the Si-H bond of the bidentate silyl ligand o-Ph2P(C6H4)SiMe2H (1) by Fe(PMe3)4. 2 showed good to excellent catalytic activity in both the reduction of aldehydes/ketones and the dehydration of benzamide. In addition, with complex 2 as a catalyst, α,β-unsaturated carbonyls could be selectively reduced to the corresponding α,β-unsaturated alcohols. The mechanisms of the formation of 2 and the catalytic dehydration process are proposed and partly experimentally verified.
- Ren, Shishuai,Xie, Shangqing,Zheng, Tingting,Wang, Yangyang,Xu, Shilu,Xue, Benjing,Li, Xiaoyan,Sun, Hongjian,Fuhr, Olaf,Fenske, Dieter
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p. 4352 - 4359
(2018/03/26)
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- Photoiodocarboxylation of Activated C=C Double Bonds with CO2 and Lithium Iodide
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The photolysis at 254 nm of lithium iodide and olefins 1 carrying an electron-withdrawing Z-substituent in CO2-saturated (1 bar) anhydrous acetonitrile at room temperature produces the atom efficient and transition metal-free photoiodocarboxylation of the C=C double bond. The reaction proceeds well for terminal olefins 1 to form the new C-I and C-C σ-bonds at the α and β-positions of the Z-substituent, respectively, and is strongly inhibited by polar protic solvents or additives. The experimental results suggest that the reaction channels through the radical anion [CO2?-] in acetonitrile, yet involves different intermediates in aqueous medium. The stabilizing ion-quadrupole and electron donor-acceptor interactions of CO2 with the iodide anion play a crucial role in the reaction course as they allow CO2 to penetrate the solvation shell of the anion in acetonitrile, but not in water. The reaction paths and the reactive intermediates involved under different conditions are discussed.
- Mello, Rossella,Arango-Daza, Juan Camilo,Varea, Teresa,González-Nú?ez, María Elena
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p. 13381 - 13394
(2018/11/20)
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- SYSTEMS AND METHODS FOR PRODUCING NITRILES
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An aspect of the present disclosure is a method that includes a first reacting a molecule from at least one of a carboxylic acid, an ester of a carboxylic acid, and/or an anhydride with ammonia to form a nitrile, where the first reacting is catalyzed using an acid catalyst. In some embodiments of the present disclosure, the molecule may include at least one of acetic acid, lactic acid, and/or 3-hydroxyproprionic acid (3-HPA). In some embodiments of the present disclosure, the molecule may include at least one of methyl acetate, ethyl lactate, and/or ethyl 3-hydroxypropanoate (ethyl 3-HP). In some embodiments of the present disclosure, the anhydride may be acetic anhydride.
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Page/Page column 5; 6
(2017/09/08)
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- CATALYTIC ESTER DECARBONYLATION
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A process of preparing olefins of the formula (I) is described herein: with R1 being a substituted or unsubstituted (C1-C30)hydrocarbyl, and R2 being a substituted or unsubstituted (C1-C20)hydrocarbyl. The process includes reacting a compound of formula (II) wherein Ar is chosen from in the presence of a palladium-based catalyst and an organic solvent. A process of preparing olefins of the formula (III) is also described: with R3 being a substituted or unsubstituted (C1-C30)hydrocarbyl, R4 being a substituted or unsubstituted (C1-C20)hydrocarbyl, and R5 being a substituted or unsubstituted (C1-C30) hydrocarbyl. The process includes reacting a compound of formula (IV) wherein Ar is chosen from with a compound of formula (V) wherein Ar is chosen from in the presence of a palladium-based catalyst and an organic solvent.
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Paragraph 0071-0072; 0074
(2016/08/07)
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- Simple Copper Catalysts for the Aerobic Oxidation of Amines: Selectivity Control by the Counterion
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We describe the use of simple copper-salt catalysts in the selective aerobic oxidation of amines to nitriles or imines. These catalysts are marked by their exceptional efficiency, operate at ambient temperature and pressure, and allow the oxidation of amines without expensive ligands or additives. This study highlights the significant role counterions can play in controlling selectivity in catalytic aerobic oxidations.
- Xu, Boran,Hartigan, Elizabeth M.,Feula, Giancarlo,Huang, Zheng,Lumb, Jean-Philip,Arndtsen, Bruce A.
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supporting information
p. 15802 - 15806
(2016/12/16)
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- A process for production of acrylonitrile
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The invention discloses an acrylonitrile production process. According to the process, acrylonitrile is produced through reacting propylene with ammonia, wherein the mole ratio of propylene to ammonia is 1.15; the conversion rate of impurity oxazole produced during the acrylonitrile production is greatly reduced to 0.01wt% through controlling the mole ratio of acrylonitrile production to 1.15.
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Paragraph 0015; 0016
(2017/03/08)
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- PROCESS FOR THE PRODUCTION OF NITRILES USING A CATALYST BASED ON ANTIMONY AND IRON
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A compound of the formula SbxFe1Oy (1) in which x varies from 0.4 to 1 inclusive and y varies from 1.6 to 4 inclusive, may be used as a catalyst for catalysing the ammoxidation reaction of an alcohol of following formula (II) CH2═C(R1)—CH2—OH (II) in which R1 represents a hydrogen atom or a methyl radical, to give nitrile of following formula (III) CH2═C(R1)—C≡N (III) in which R1 has the same meaning as in above formula (ii), the said reaction being carried out in the gas phase, the said gas phase comprising at least oxygen and ammonia. The present invention also relates to the process for the ammoxidation of an alcohol of formula (II) employing a compound of formula (I) as catalyst.
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Paragraph 0050; 0051; 0052; 0053
(2016/02/16)
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- Oxide catalyst, process for producing oxide catalyst, process for producing unsaturated acid, and process for producing unsaturated nitrile
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Disclosed is a process for producing an oxide catalyst for use in the gas-phase catalytic oxidation reaction or the like of propane or the like, the process comprising the steps of: (I) obtaining a preparation containing compounds of Mo, V, Nb, and Sb or Te at the predetermined atomic ratios; (II) drying the preparation to obtain a dry powder; and (III) calcining the dry powder, wherein the step (III) comprises the step of calcining the dry powder in the presence of a compound containing W in the form of a solid to obtain a pre-stage calcined powder or a mainly calcined powder, or the step of calcining the dry powder and calcining the obtained pre-stage calcined powder in the presence of the solid to obtain a mainly calcined powder, the solid satisfies the predetermined conditions, and the oxide catalyst comprises a catalytic component having the predetermined composition.
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Page/Page column 45
(2016/09/26)
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- APPARATUS FOR PRODUCING MIXED SOLUTION AND METHOD FOR PREPARING MIXED SOLUTION
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An apparatus for producing a mixed solution, comprising a mixing vessel for preparing an aqueous mixed solution containing a dicarboxylic acid and an Nb compound and a filter for the aqueous mixed solution connected to the mixing vessel via a pipe, the mixing vessel being anticorrosive and equipped with a stirring unit, a heating unit and a cooling unit for the aqueous mixed solution, wherein the aqueous mixed solution prepared in the mixing vessel is fed to the filter via the pipe and filtered in the filter under increased pressure.
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Paragraph 0191; 0191
(2016/12/16)
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- Efficient reductive dehydration of primary amides to nitriles catalyzed by hydrido thiophenolato iron(II) complexes under hydrosilation conditions
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The reductive dehydration of amides to nitriles under hydrosilation conditions with hydrido thiophenolato iron(II) complexes [cis-Fe(H)(SAr)(PMe3)4] (1–4) as catalysts is reported using (EtO)3SiH as an efficient reducing agent in the yields up to 93%. The merits of this catalytic system, the low catalyst loadings (2?mol%) and the amount of efficient reducing agent (EtO)3SiH, make this method more attractive.
- Xue, Benjing,Sun, Hongjian,Wang, Yan,Zheng, Tingting,Li, Xiaoyan,Fuhr, Olaf,Fenske, Dieter
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p. 148 - 150
(2016/09/07)
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- METAL COMPLEX, AND METHOD FOR SYNTHESIS OF NITROGEN-CONTAINING ORGANIC COMPOUND USING METAL COMPLEX
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PROBLEM TO BE SOLVED: To provide a method that synthesizes a nitrogen-containing organic compound under a relatively mild condition and in a relatively simple process. SOLUTION: A method that synthesizes a nitrile compound includes a step for the reaction between an acid chloride and a complex represented by formula (1A) or formula (1B) (M1-M7 independently represent Ti, Zr, Hf, V, or the like; L1-L7 independently represent a ligand comprising a substituted/unsubstituted cyclopentadienyl derivative, a diphenylamine ligand or the like). SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0094-0095
(2017/04/29)
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- Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism
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A minimal cell can be thought of as comprising informational, compartment-forming and metabolic subsystems. To imagine the abiotic assembly of such an overall system, however, places great demands on hypothetical prebiotic chemistry. The perceived differences and incompatibilities between these subsystems have led to the widely held assumption that one or other subsystem must have preceded the others. Here we experimentally investigate the validity of this assumption by examining the assembly of various biomolecular building blocks from prebiotically plausible intermediates and one-carbon feedstock molecules. We show that precursors of ribonucleotides, amino acids and lipids can all be derived by the reductive homologation of hydrogen cyanide and some of its derivatives, and thus that all the cellular subsystems could have arisen simultaneously through common chemistry. The key reaction steps are driven by ultraviolet light, use hydrogen sulfide as the reductant and can be accelerated by Cu(I)-Cu(II) photoredox cycling.
- Patel, Bhavesh H.,Percivalle, Claudia,Ritson, Dougal J.,Duffy, Colm D.,Sutherland, John D.
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p. 301 - 307
(2015/04/14)
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- Production of acrylonitrile
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PROBLEM TO BE SOLVED: To provide a novel method of producing acrylonitrile, wherein propylene and propane derived from a fossil resource are used as raw materials.SOLUTION: The method of producing the acrylonitrile includes: a step (1) of dehydrating glycerin to obtain acrolein; and a step (2) of subjecting the resultant acrolein to ammoxidation at 300-400°C.
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Paragraph 0085
(2017/01/02)
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- METHOD FOR PRODUCING ACRYLONITRILE
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The invention relates to a method for producing acrylonitrile which includes a vapor phase catalytic ammoxidation process of performing vapor phase catalytic ammoxidation by bringing a source gas containing propylene, molecular oxygen, and ammonia into contact with a fluidized bed catalyst to obtain acrylonitrile. The method is characterized in that the fluidized bed catalyst is a catalyst containing iron, antimony, and tellurium, and the vapor phase catalytic ammoxidation process is performed while maintaining an adsorbed amount of ammonia per specific surface area (m2/g) of the fluidized bed catalyst in the range of 0.01 to 0.22 μmol/m2. According to the method for producing acrylonitrile of the invention, it is possible to stably maintain a high acrylonitrile yield over a long period of time.
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Paragraph 0092-0121
(2015/01/18)
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- METHOD FOR PRODUCING ACRYLONITRILE
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The invention relates to a method for producing acrylonitrile which includes a vapor phase catalytic ammoxidation process of performing vapor phase catalytic ammoxidation by bringing a source gas containing propylene, molecular oxygen, and ammonia into contact with a fluidized bed catalyst to obtain acrylonitrile. The method is characterized in that the fluidized bed catalyst consists of particles containing Fe, Sb, and Te, and the vapor phase catalytic ammoxidation process is performed while maintaining a B/A in the range of 2.0 to 5.0, where A denotes an atomic ratio of Te/Sb in a bulk composition of the fluidized bed catalyst and B denotes an atomic ratio of Te/Sb in a surface composition of the particles of the fluidized bed catalyst. According to the method for producing acrylonitrile of the invention, it is possible to stably maintain a high acrylonitrile yield over a long period of time.
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Paragraph 0088-0103
(2015/01/18)
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- METHOD FOR PRODUCING ACRYLONITRILE
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The invention relates to a method for producing acrylonitrile which includes a vapor phase catalytic ammoxidation process of performing vapor phase catalytic ammoxidation by bringing a source gas containing propylene, molecular oxygen, and ammonia into contact with a fluidized bed catalyst to obtain acrylonitrile. The method is characterized in that the fluidized bed catalyst is a catalyst containing molybdenum and bismuth and the vapor phase catalytic ammoxidation process is performed while maintaining an adsorbed amount of ammonia per specific surface area (m2/g) of the fluidized bed catalyst in the range of 0.05 to 0.6 μmol/m2. According to the method for producing acrylonitrile of the invention, it is possible to stably maintain a high acrylonitrile yield over a long period of time.
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Paragraph 0098-0127
(2015/01/18)
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- METHOD FOR PURIFYING ACRYLONITRILE
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Condenser in tower affection using a distillation column is connected, acrylonitrile, including solution of hydrogen cyanide and water distilling said partial flow and method for purifying acrylonitrile as including process, said an outlet of the condenser be maintained constant temperature of fluid provides including method process.
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Paragraph 0088-0099
(2017/01/02)
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- Olefins from biomass feedstocks: Catalytic ester decarbonylation and tandem Heck-type coupling
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With the goal of avoiding the need for anhydride additives, the catalytic decarbonylation of p-nitrophenylesters of aliphatic carboxylic acids to their corresponding olefins, including commodity monomers like styrene and acrylates, has been developed. The reaction is catalyzed by palladium complexes in the absence of added ligands and is promoted by alkali/alkaline-earth metal halides. Combination of catalytic decarbonylation and Heck-type coupling with aryl esters in a single pot process demonstrates the viability of employing a carboxylic acid as a "masked olefin" in synthetic processes. This journal is
- John, Alex,Hogan, Levi T.,Hillmyer, Marc A.,Tolman, William B.
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supporting information
p. 2731 - 2733
(2015/03/05)
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- PCC-Promoted dehydration of aldoximes: A convenient access to aromatic, heteroaromatic, and aliphatic nitriles
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A simple and convenient procedure for the synthesis of nitriles by dehydration of aldoximes using a PCC (pyridiniumchlorochromate) has been developed. A variety of aromatic, heteroaromatic, and aliphatic aldoximes are converted. Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications for the full spectral details.
- Chandrappa,Prasanna,Vinaya,Prasanna,Rangappa
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p. 2756 - 2762
(2013/08/23)
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- METHOD FOR PRODUCING UNSATURATED NITRILE
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A method for producing an unsaturated nitrile by subjecting propane to a vapor-phase catalytic ammoxidation reaction using a fluidized bed reactor in the presence of a composite oxide catalyst containing Mo, V, and Nb, the method comprising the step of: adding a tungsten compound into the fluidized bed reactor to adjust a molar ratio (W/Mo ratio) of tungsten contained in a tungsten compound to molybdenum contained in the composite oxide catalyst that exist within the fluidized bed reactor so that the molar ratio is in the range of 0.0001 to 0.1.
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Paragraph 0132
(2013/10/22)
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- METHOD FOR PRODUCING UNSATURATED NITRILE
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A method for producing an unsaturated nitrile by a propane ammoxidation reaction, the method including: a step of measuring at least one physical property value selected from the group consisting of the normalized UV value and the reduction ratio of a catalyst contained in a reactor, and a step of maintaining or changing a reaction condition based on the measured physical property value.
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Paragraph 0232
(2013/12/03)
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- Molecular products from the thermal degradation of glutamic acid
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The thermal behavior of glutamic acid was investigated in N2 and 4% O2 in N2 under flow reactor conditions at a constant residence time of 0.2 s, within a total pyrolysis time of 3 min at 1 atm. The identification of the main pyrolysis products has been reported. Accordingly, the principal products for pyrolysis in order of decreasing abundance were succinimide, pyrrole, acetonitrile, and 2-pyrrolidone. For oxidative pyrolysis, the main products were succinimide, propiolactone, ethanol, and hydrogen cyanide. Whereas benzene, toluene, and a few low molecular weight hydrocarbons (propene, propane, 1-butene, and 2-butene) were detected during pyrolysis, no polycyclic aromatic hydrocarbons (PAHs) were detected. Oxidative pyrolysis yielded low molecular weight hydrocarbon products in trace amounts. The mechanistic channels describing the formation of the major product succinimide have been explored. The detection of succinimide (major product) and maleimide (minor product) from the thermal decomposition of glutamic acid has been reported for the first time in this study. Toxicological implications of some reaction products (HCN, acetonitrile, and acyrolnitrile), which are believed to form during heat treatment of food, tobacco burning, and drug processing, have been discussed in relation to the thermal degradation of glutamic acid.
- Kibet, Joshua K.,Khachatryan, Lavrent,Dellinger, Barry
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p. 7696 - 7704
(2013/09/02)
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- Structure and photochemistry of a novel tetrazole-saccharyl conjugate isolated in solid argon
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A combined matrix isolation FTIR and theoretical DFT/B3LYP/6-311++G(3df, 3pd) study of the novel synthesised tetrazole-saccharyl conjugate 2-[1-(1H-tetrazol-5-yl)ethyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide [1-TE-BZT] was performed. In the gas phase, at room temperature, the compound exists as a mixture of six isomeric forms (four conformers of 1H tautomer and two conformers of 2H tautomer). According to theoretical calculations, conformers 1H were the most stable and the relative energies among the three most stable forms are lower than 4 kJ mol-1. These conformers benefit from stabilising intramolecular hydrogen bonds-like interactions involving the 1H of the tetrazole ring and the carbonyl oxygen of the saccharyl moiety. The photochemistry of 1-TE-BZT in solid argon was investigated and theoretical DFT/B3LYP/6-311++G(3df,3pd) calculations also helped in assignment of the experimental bands. A quick consumption of the compound occurred after irradiation of the matrix with UV laser light at λ = 275 nm. Three photofragmentation pathways were proposed, one leading to 2-[1-(1H-diaziren-3- yl)ethyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide and molecular nitrogen, a second one giving 2-(1,1-dioxide-3-oxo-1,2-benzisothiazol-2(3H)-yl) propanenitrile and azide, and a third one involving loss of azide from the tetrazole ring and decarbonylation of the saccharyl ring of 1-TE-BZT to give acrylonitrile and 7-thia-8-azabicyclo[4.2.0] octa-1,3,5-triene 7,7 dioxide. The comparison of the relative intensities of the bands of the photoproducts obtained from the three channels allowed us to consider the latter pathway, involving an unprecedented photocleavage of the benzisothiazole (saccharyl) ring, as the preferred photodegradation channel of 1-TE-BZT.
- Ismael, A.,Cristiano, M. L. S.,Borba, A.,Duarte, L.,Giuliano, B. M.,Gomez-Zavaglia, A.
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p. 105 - 116,12
(2020/08/20)
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