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1.
    
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The amount of oxygen chemisorbed on molybdena-alumina catalysts at room temperature has been determined by a pulse chromatographic technique. The variation of molybdenum dispersity with its concentration and the calcination temperature is discussed.
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2.
The problem of predicting the activity of oxide and carbonate catalysts for some reactions of petrochemical synthesis (vapor phase conversion of carboxylic acids, catalytic oxidation of asphaltic tar to bitumen) according to the established dependence of thermal stability variations of intermediates on the formation enthalpy of metal oxides or standard ele.trode potentials is discussed.
, ( , ) .
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3.
Zirconia is well known as a promising support for active metallic centers but it is also by itself an interesting catalyst for reactions involving hydrogen in particular. This paper describes the catalytic properties of ZrO2-obtained in the form of an aerogel-, towards butene-1-isomerization and/or its hydrogenation at low temperature. Activation at 430°C in vacuum led to the best results in cis-trans isomerization in the temperature range of 80–200°C. It is shown that at temperatures 150°C a carbanion mechanism is operating while at higher temperatures the thermodynamic selectivity is attained. Selective poisoning experiments by NH3 or CO2 were carried out in order to identify the catalytic sites for the isomerization of n-butene.
, , . ZrO2, , / -1 . 430°C - 80–200°C. , 150°C , . NH3 CO2 -.
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4.
Kinetics of p-xylene oxidation in an aqueous system catalyzed by cobalt oxide have been studied at 140 °C under oxygen. The reaction is second order in p-xylene and first order in cobalt oxide concentration. The rate constant and product distribution are very close to those found for homogeneous catalytic reactions. Based on these findings, a reaction scheme describing the influence of oxide catalyst is formulated. - , , 140° C . - . , . , .  相似文献   

5.
Vanadyl -and -polyphosphates in vapor phase oxidation of 2-methylpyridine show comparable activity and selectivity to the formation of pyridine-2-carboxaldehyde as traditional vanadium-molybdeum oxide catalysts. A redox mechanism for the reaction of 2-methylpyridine oxidation on vanadyl polyphosphates is suggested with interaction between 2-methylpyridine and oxygen of the catalyst lattice as the rate-determining step.
- - 2- -- . - 2- . - 2- .
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6.
Sodium perborate was used for oxidation of bromide ions at pH 3.64. The reaction was conducted by potentiometric measurements. The orders with respect to perborate and bromide ions were found to be unity in each reagent and a plausible mechanism was postulated. The effect of temperature was studied in the range of 20–40 °C and the Arrhenius parameters were evaluated.
pH=3,64. . , . 20–40 °C, .
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7.
The catalytic incineration of n-hexane over a Pt/Al2O3 catalyst has been studied using a fixed bed reaction. The reaction was carried out in dry air between 250 and 350 °C and at 1 atm pressure. The concentration of n-hexane was between 25 and 300 ppm. The reaction was found to be zero order in n-hexane concentration and the activation energy was found to be 21 kcal/mol. The zero order kinetics can be explained by a surface redox cycle known as Mars-van Krevelen mechanism in which the oxidation of surface Pt is the rate-controlling step.
- Pt/Al2O3 . , 250–350°C 1 . - 25–300 .. - –21 /. , — , , , Pt.
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8.
The heat of formation of some copper clusters in a MgO lattice has been calculated by the interacting bonds method.
MgO.
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9.
Oxidation rates and k2/k6 ratios are given for some acids from propionic to lauric. The k2/k6 ratio is shown to be influenced by the electrostatic effect of the solvent. A linear dependence between the isodielectric values of k2/k6 and the number of methylene groups in the acid molecules is described.
k2/k6 . k2/k6 k2/k6 .
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10.
The influence of oscillations in the feed concentration on the selectivity of a catalytic process has been studied for parallel reactions. The selectivity increase in periodic operations depends on both the type of kinetic functions and the non-steady-state properties of the catalysts.
. , .
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11.
The state of adsorption layers and adsorption kinetics of C2H4/Ir (110) at 300–1000 K has been studied using XPS method.
C2H4/Ir (110) 300–1000 K.
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12.
    
By the XPS method it has been shown that in the catalysts obtained by interacting W(-C4H7)4 with SiO2 several oxidation states of the supported tungsten are realized together with a higher coverage of the silica surface with tungsten compounds, as compared with the catalysts prepared by impregnation of SiO2 with an aqueous solution of (NH4)2 WO4.
, , W(-C4H7)4 SiO2, , , SiO2 (NH4)2 WO4.
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13.
The thermal treatment of Pd catalysts in a reducing atmosphere of hydrogen leads to interaction of supported metal and support to form solid solutions.
, .
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14.
    
, . .
The existence of positive steady states for the kinetic equations of reversible reactions has been proved. An iteration procedure is proposed for locating the steady states. The results of model calculations are discussed.
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15.
It has been shown that hydrogen determined from the TPD curves of platinum saturated with hydrogen sorbed above room temperature is chiefly absorbed and not adsorbed hydrogen; this absorbed hydrogen has no effect on the charging curve.
, , , , ; .
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16.
The study describes the mathematical model, calculation and optimization of the technological scheme of the regeneration of the catalytic solution in the liquid-phase oxidation of hydrocarbons.
, .
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17.
The effect of the state of adsorbed layers on the formation of monomeric and dimeric benzene cation-radicals (CR) on ZSM-5 zeolites has been studied. Removal of benzene is shown to be accompanied by disappearance of CR, which is reversible and takes place with preservation of the sites for their stabilization.
- (KP) ZSM-5. , KP, .
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18.
The thermal decomposition of Cu(I) phosphine complexes of the general types (CuXPPh3)4, [CuX(PPh3)2] and [CuX(PPh3)3] was investigated.The thermal decomposition of (CuXPPh3)4, where X denotes Cl, Br, I, NO 3 and PPh3=P(C6H5)3, occurs with formation of a phosphine oxide intermediate. For the remaining complexes this intermediate was not proved in the thermal decomposition.
Zusammenfassung Die thermische Zersetzung der Cu(I)-Phosphinkomplexe vom allgemeinen Typ (CuXPPh3)4 und [CuX(PPh3)2], wie auch [CuX(PPh3)3] wurde untersucht. Die thermische Zersetzung von (CuXPPh3)4, wobei X=Cl, Br, I und NO 3 bedeutet und PPh3=P(C6H5)3, verläuft unter Bildung eines Phosphinoxid Zwischenproduktes, bei den übrigen Komplexen konnte dieses im Laufe der thermischen Zersetzung nicht nachgewiesen werden.

Résumé On a étudié la décomposition thermique des complexes phosphine-Cu(I) de formule générale (CuXPPh3)4, [CuX(PPh3)2], [CuX(PPh3)3]. La décomposition thermique de (CuXPPh3)4, où X désigne Cl, Br, I et NO 3 , et PPh3=P(C6H5)3, s'effectue avec formation d'un oxyde de phosphine intermédiaire; avec les autres complexes, cet intermédiaire n'a pas été mis en évidence au cours de la décomposition thermique.

(CuXPPb3)4 [CuX(PPh3)2] [CuX(PPh3)3]. (CuXPPh3)4, X=Cl, Br, I, NO 3 , PPh3=(65)3 . .
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19.
Field emission microscopy and thermal desorption studies of nitrogen adsorption on a monocrystal tip and a polycrystalline rhenium wire indicate the formation of molecular () and dissociative () forms of adsorption. Adsorption-desorption characteristics have been measured.
. - - , - .
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20.
The influence of non-equilibrium vibrational excitation of CH3F molecules on the rate of their reaction with bromine atoms has been investigated. A three-fold increace in the reaction rate has been registered at CH3F and Br2 pressures of 0.07 Torr and at 100°C. The increase is shown not to be associated with equilibrium thermal heating.
CH3F . CH3F Br2 0,07 100°C. , .
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