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1.
The reaction of NH3 with R–CHO (R=CH3, Ph) has been studied. Experimental data and parameters of the laboratory catalytic reactor are reported.
NH3 c R–CHO(R=CH3, Ph). .
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2.
    
Ni-, Pt-, Pd-, Rh-. , : Rh>Ni>Pt>Pd.
The hydrogenation of citral to citronellal has been studied on Raney nickel, platinum, palladium and rhodium blacks. The selectivity of hydrogenation of the conjugated double bond was found to decrease in the order Rh>Ni>Pt>Pd.
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3.
It has been established that porpylene oxidation to acrolein on a multicomponent oxide catalyst containing Mo, Bi, Fe, Ni, Co, K, P and SiO2 follows an alternating oxidation-reduction mechanism and involves the participation of lattice oxygen with the bond energy of about 280 kJ/mol.
, Mo, Bi, Fe, Ni, Co, K, P SiO2 280 /.
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4.
Attempts have been made to correlate the Si/Al atom ratio, the degree of crystallinity, crystallite dimensions and the mean diameter of crystalline particles with the relative adsorption affinity index (RAI). Differences in molecular sieving effect and in some diffusional aspects between traditional zeolites and the new shape-selective ZSM are revealed by the adsorption characteristics of cyclohexane, benzene, toluene, neopentane and xylenes.
Si/Al , , , (RAI). - ZSM , , , .
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5.
Genesis and structure of Raney nickel catalysts modified by Mo, Fe and Ca have been studied by XPS, SIMS and Auger and electron microprobe methods. It has been established that these catalysts are inhomogeneous and their structure can be described by models accounting for the interaction and localization character of metal components, their oxides and hydroxides.
, - Ni-, Mo, Fe Ca. , , , .
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6.
The thermal investigation of the reaction taking place between dichromates and oxalates in the solid state has been done taking two systems of potassium dichromate-potassium oxalate and sodium dichromate-sodium oxalate. The techniques employed include thermogravimetry, differential thermal analysis, infrared spectroscopy and X-ray diffraction studies. The results indicate a stoichiometric reaction of dichromate and oxalate in 11 ratio to give the corresponding chromate as the sole product.
Zusammenfassung Anhand der Systeme Kaliumdichromat-Kaliumoxalat bzw. Natriumdichromat-Natriumoxalat wurde eine thermische Untersuchung der Festkörperreaktion zwischen Dichromaten und Oxalaten durchgeführt. Dazu wurden thermogravimetrische, dififerentialthermoanalytische, IR-spektroskopische und Röntgendiffraktionsverfahren angewendet. Im Ergebnis zeigte sich eine stöchiometrische Reaktion von Dichromat und Oxalat im Verhältnis 11, die das entsprechende Chromat als einziges Produkt liefert.

, , — — . , 11 .
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7.
The effects of diethylene glycol on the hydration characteristics of tricalcium silicate and tricalcium aluminate pastes were studied. Diethylene glycol acts as a retarder in the hydration of C3S, and as an accelerator in the hydration of C3A. The amount of Ca(OH)2 found in pastes of C3S treated with diethylene glycol was lower, the induction period increased and the formation of hydrates was retarded. For C3A pastes, hydration in the presence of diethylene glycol accelerated the formation of the hexagonal aluminate hydrates and promoted the conversion to the cubic form.
Zusammenfassung Der Einfluss von Diethylenglykol auf die Hydratation von Tricalciumsilicat- (C3S) und Tricalciumaluminat- (C3A) -Pasten wurde untersucht. Diethylenglykol verzögert die Hydratation des C3S und beschleunigt die des C3A.In C3S-Proben, die mit Diethylenglykol hydratisiert wurden, ist der Gehalt an Ca(OH)2 geringer, die Induktionsperiode länger und die Bildung von Hydraten verzögert. In C3A-Pasten wird in Gegenwart von Diethylenglykol die Bildung des hexagonalen Calciumaluminathydrats beschleunigt und seine Umwandlung in die kubische Form begünstigt.

. , . , , , , , . .
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8.
The rate of methane formation on zinc-chromium catalysts is described by zero-order rate law, If the catalyst is activated by copper, the rate of methane formation increases due to a decrease in the activation energy of the reaction. Presumably the formation of methane and methanol takes place on different active centers.
, . , . , .
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9.
The kinetics of the oxidation of ascorbic acid by [(NH3)5RuORu(NH3)4ORu(NH3)5]7+ has been studied by the stopped-flow method. The activation parameters have been calculated and a possible mechanism is suggested.
[(NH3)5RuORu(NH3)4ORu·(NH3)5]7+ . .
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10.
The kinetics of isothermal decomposition of solid K2Zr2(O2)2F6·2H2O have been studied in the temperature range 100–226° under vacuum. The fractional decomposition has been determined by measuring the pressure of evolved oxygen during pyrolysis with the help of a McLeod gauge. The values ranged from 0.05 to 0.62. The vs. t data showed that the kinetics are deceleratory throughout the course of the reaction. The initial part of the decomposition reaction could be best described by a unimolecular decay law, while the later stages obey contracting volume kinetics. The activation energies have been determined and the respective values for the above stages are 13.6 and 6.9 kcal·mole–1.
Zusammenfassung Die Kinetik der isothermen Zersetzung von festen K2Zr2(O2)2F6·2H2O wurde im Temperaturbereich von 100–226° im Vakuum untersucht. Die fraktionierte Zersetzung wurde durch Messung des Druckes des während der Pyrolyse entwickelten Sauerstoffs mit einem McLeod-Manometer bestimmt. Die -Werte variierten von 0.05 bis 0.62. Die -t Daten zeigen, daß die Kinetik im Verlauf der Reaktion herabgesetzt wird. Der erste Teil der Zersetzungsreaktion konnte am besten durch ein unimolekulares Zerfallgesetzt beschrieben werden, während die späteren Phasen der Kinetik der Volumenkontraktion gehorchten. Die Aktivierungsenergien wurden berechnet und die entsprechenden Werte für obige Reaktionen ergaben sich 13.6 bzw. 6.9 Kcal mol–1.

K2Zr2(O2)2F6·22 100–226°. «» , , . «» 0.05 0.62. –t , . , — . , , , 13.6 6.9 .–1.


One of the authors (SMK) is grateful to I.I.T. Delhi for a research scholarship.  相似文献   

11.
The effect of electrochemical H+ pumping on the hydrogenation rate of ethylene on Ni electrode catalysts in a solid proton-conducting electrolyte cell has been studied.
Ni — .
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12.
The chemisorption of hydrogen on Ni/SiO2 has been studied by measuring temperature programmed desorption on various samples under various experimental conditions. Two peaks are found, which can be related to a weakly and to a strongly bound species of chemisorbed hydrogen. Their analysis has been performed by a method which makes possible to determine whether a certain kinetic model can describe the entire desorption process or to assign a clear meaning to the corresponding kinetic parameters.
Ni/SiO2 - . . , , , , .
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13.
IR spectra of adsorbed alcohols on alumina were measured under the reaction conditions at elevated temperatures. The transient response of IR absorption intensity indicates that alkoxides are reactive adsorbed species but carboxylates are not. The rate constants of surface reactions were calculated from the transient response.
, . , , , —, .
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14.
The effects of active (carbon dioxide and carbon monoxide) and neutral (helium, argon and nitrogen) atmospheres on the course of thermal decomposition of oxalates have been studied and compared. A mechanism of thermal decomposition has been proposed on the basis of the results obtained, the first stage of which consists in a heterolytic dissociation of the C-C bond, with the formation of carbon dioxide and the CO 2 2– anion.
Zusammenfassung Die Effekte von aktiven (Kohlendioxid und Kohlenmonoxid) und neutralen (Helium, Argon, Stickstoff) Atmosphären auf den Verlauf der thermischen Zersetzung von oxalaten wurden untersucht und miteinander verglichen. Aus den erhaltenen Ergebnissen wird ein Mechanismus der thermischen Zersetzung abgeleitet, dessen erster Schritt die heterolytische Dissoziation der C-C-Bindung unter Bildung von CO2 und des CO 2 2– -Anions ist.

(- ) (, ) . , C-C CO 2 2– .
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15.
Heat treatment of porous glasses results in a migration of boron to the surface changing surface acidity. The surface acidity of thermally modified porous glasses was characterized by NH3 desorption and the catalytic activity for conversion of alcohols was investigated.
, . NH3, .
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16.
A pulse chromatographic method based on the reaction of gaseous dimethylzinc tetrahydrofura nate was developed for the determination of surface hydroxyl groups and/or adsorbed water in solid porous materials. The procedure is rapid and gives results comparable to other methods. Some heterogeneous catalysts and supports have been analyzed.
, , / , . , . .
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17.
In hydrogenation over metals (M)j carbon monoxide is adsorbed as a molecule. C–O bond rupture in partially hydrogenated complex, MCHOH, leads to MO and MCH2 and then to hydrocarbons, while transformation of MCHOH into MCH2OH gives alcohols and other oxygen-containing compounds. Selectivity towards hydrocarbons increases with increasing energy of M–O bonds.
(M) . C–O MCHOH MO MCH2 — ; MCHOH MCH2OH . M–O.
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18.
Pyrolysis in combination with gas chromatography and thermogravimetry were used to study the thermal degradation of some cross-linked copolymers of vinyl acetate with divinylbenzene and ethylstyrene. The temperature was varied in the range 200° and 800°. The thermal decomposition products of the analyzed copolymers vary greatly, both with the temperature and with the composition of the samples. The experimental data obtained led to the assumption of a complex degradation mechanism, evidenced by the overlapping processes and the unexpected contents of certain evolved compounds as a function of composition.
Zusammenfassung Pyrolyse in Kombination mit Gaschromatographie und Thermogravimetrie wurde zu Untersuchung des thermischen Abbaus einiger vernetzter Kopolymere von Vinylacetat mit Divinylbenzol und Äthylstyrol herangezogen. Die Temperatur wurde im Bereich von 200–800° variiert. Die thermischen Zersetzungsprodukte sind sehr unterschiedlich, abhängig von der Temperatur und der Zusammensetzung der Probe. Aus den experimentellen Daten wird auf einen komplexen Zersetzungsmechanismus geschlossen, der durch die Überlappung der Prozesse und durch das auftreten bestimmter unerwarteter Verbindungen in Abhängigkeit von der Zusammensetzung bestätigt wird.

. 200–800°. , . , .
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19.
Results on the thermal decomposition of iron(II) sulphate heptahydrate in the presence of basic magnesium carbonate are presented and discussed. These results are compared with those for the mixture of iron(II) sulphate heptahydrate with basic beryllium carbonate. While no reaction occurs between the components in the case of basic beryllium carbonate, basic magnesium carbonate reacts readily with iron(II) sulphate heptahydrate.
Zusammenfassung Bei der in Gegenwart von basischem Magnesiumcarbonat erfolgten thermischen Zersetzung von Eisen(II)-sulfat-Heptahydrat erhaltene Ergebnisse werden beschrieben, diskutiert und mit denen verglichen, die in Gegenwart von Berylliumcarbonat erhalten wurden. Im Gegensatz zu basischem Berylliumcarbonat reagiert basisches Magnesiumcarbonat mit Eisen(II) sulfat-Heptahydrat.

. . , , .


The author gratefully acknowledges the support extended by Professor P. K. Jena, Director of this laboratory, and the permission to publish the results.  相似文献   

20.
Nitric oxide adsorption on the surface of a Co–Al catalyst was investigated using infrared technique. The presence of two kinds of adsorbed species was confirmed by N–O stretching frequencies at 1780 and 1855 cm–1. The effect of potassium added to the Co–Al catalyst was examined.
Co–Al . N–O : 1780 1855 –1. , Co–Al.
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