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1.
In this paper we calculate the effect of surface OH/OH– on the simultaneous adsorption of H2 and O2 on ZnO. A quantitative comparison between H2 and CO oxidation rates shows that the two mechanisms are similar for the same water recovery on ZnO.
OH/OH– H2 O2 ZnO. H2 CO , ZnO.相似文献
2.
The kinetics of methanol synthesis performed in a flow circulation installation in the presence of low-temperature copperzinc-aluminium catalyst has been investigated. The application of a power kinetic equation describing the surface chemical interaction on an exponentially inhomogeneous surface is established. The effect of the volume rate and the temperature is studied and the presence of a compensation effect is proved. A possibility of determination of the temperature and the volume rate, under which conditions the side-reactions do not affect the main one, is shown on the basis of the kinetic investigations.
-- - . - - . . , .相似文献
3.
Yu. I. Aristov A. I. Volkov V. N. Parmon K. I. Zamaraev 《Reaction Kinetics and Catalysis Letters》1984,25(3-4):329-334
Tunneling electron transfer from bulk F+-centers of MgO to molecules of N2O adsorbed on MgO surface has been detected and studied.
F+- N2O, .相似文献
4.
V. P. Sokolov N. M. Zaidman V. I. Shport Y. A. Alabuzhev 《Reaction Kinetics and Catalysis Letters》1977,6(3):329-333
Under reforming conditions, the rate of n-heptane conversion on a large Pt/Al2O3 catalyst grain, in contrast to that in the kinetic region, depends on the hydrogen to hydrocarbon mole ratio. The rate equation for the reaction on a large grain agrees well with the experimental results obtained by a gradientless method under pressure.
- , , : . , .相似文献
5.
It has been found that nitrobenzene, in the presence of monoolefins, is effectively hydrogenated with the cobaloxime catalyst. Conjugated dienes and nitrobenzene are both hydrogenated; the extent of hydrogenation of dienes depends upon the structure. A remarkable exception is isoprene, whose presence in the reacting solution completely inhibits the hydrogenation of nitrobenzene. No organometallic compounds of Co(III) have been isolated. Homolytic activation of hydrogen is therefore rather unlikely in this system.
, . , , , . , . - Co(III). , , - .相似文献
6.
L. I. Kuznetsova M. A. Fedotov E. N. Yurchenko 《Reaction Kinetics and Catalysis Letters》1989,39(2):393-398
In aqueous solution, PM12–nVnO40
–(3+n) (M=Mo,W) hetero-polyanions provide a much faster oxidation of NO than mononuclear VO
2
+
ions, yielding HNO2, NO
3
–
and reduced HPA.
, PM12–nVnO40 –(3+n) (M=Mo,W) , VO 2 + , NO HNO2 NO 3 – .相似文献
7.
The applicability of the BEBO relationship describing the change in potential energy along the minimum energy path has been studied by carrying out calculations with the BEBO and a modified BEBO procedure.
BEBO BEBO BEBO.相似文献
8.
W. K. Jówiak 《Reaction Kinetics and Catalysis Letters》1986,30(2):345-351
Based on TPR investigations of oxidized 5 % Rh/ZrO2 catalyst a substantial effect of rhodium both on increase in degree of surface reduction of the support and lowering of reduction temperature range as compared to the support alone was observed. With growing reoxidation temperature, a gradual increase in degree of oxidation of rhodium takes place until Rh2O3 is formed at temperature about 770 K. Simultaneously, the support surface is gradually reoxidized until a prilmary state is reporduced at 720–779 K.
5% Rh/ZrO2, , . , Rh2O3 770 . , , 720–770 .相似文献
9.
Generation of gradientless conditions by the pulsation method with variable reciprocating gas flow method through the isothermal catalyst bed is suggested as one of the trends in the further development of external circulation flow systems. The conditions ensuring continuous stirring have been established. Flowcirculation and pulsation methods have been tested under similar conditions.
- - . , , - .相似文献
10.
W. M. Lin C. R. Huang S. F. Gan H. Noller 《Reaction Kinetics and Catalysis Letters》1989,39(1):207-212
The distribution of components in the HG-1 ammonia catalyst promoted by rare earth oxide (successfully developed by the authors) was analyzed by electron microprobe photography. The results enable us to explain the effect of additives upon the activity as well as the remarkably high lifetime of catalyst.
HG-1, ( ) , . , .相似文献
11.
J. Brandštetr 《Journal of Thermal Analysis and Calorimetry》1978,14(1-2):157-160
A review is given of recently developed instruments used in thermometric analysis and new methods of direct injection enthalpimetry.In the past two years, several types of Tronac (Orem, Utah) and Setaram (Lyon, France) calorimeters have been developed. A new mixing cell construction led to development of a flow instrument for automated thermometric analyses (Technicon, Tarrytown N. Y.). A new type of Hungarian instrument, Ditermanal (Orion, Budapest) permits arbitrary analyses.At the Technical University in Brno, small table twin isoperibol instruments allowing the direct analyses of solid samples have been developed. The use of PTC thermistors and a calibration device improved the accuracy of measurements.Many new methods of silicate and lime analysis, water determination, etc. have been elaborated.
Zusammenfassung Eine Übersicht über die zur thermometrischen Analyse eingesetzten, entwickelten Instrumente und neuen Methoden der Direkt-Injektion Enthalpimetrie wird gegeben.In den zwei vergangenen Jahren wurden verschiedene Kalorimetertypen TRONAC (Orem, Utah) und SETARAM (Lyon, France) entwickelt. Eine neue Mischzellenkonstruktion ermöglichte es ein Durchflussinstrument für automatische thermometrische Analysen (TECHNICON, Tarrytown, N. Y.) zu entwickeln. Ein neuer ungarischer Instrumententyp, DITERMANAL (ORION, Budapest), ermöglicht die Durchführung von Schiedsanalysen.An der Technischen Universität Brno wurden kleinen Zwillings-Isoperibol-Tisch Instrumente entwickelt, welche auch die direkten Analysen fester Proben ermöglichen. Der Einsatz von PTC-Thermistoren und einer Eichvorrichtung erhöhte die Messgenauigkeit.Viele neue Methoden der Silikat- und Kalkanalyse, Wasserbestimmungen usw. wurden erarbeitet.
Résumé On passe en revue les instruments récemment mis au point et utilisés en analyse thermométrique ainsi que les nouvelles méthodes d'enthalpimétrie par injection directe.Dans les deux dernières années, divers types de calorimètres ont été mis au point: TRONAC (Orem, Utah) et SETARAM (Lyon, France). La réalisation d'une nouvelle cellule de mélange a permis de mettre au point un appareil à flux pour les analyses thermométriques automatiques (TECHNICON, Tarrytown, N. Y.). Un nouveau type d'instrument hongrois, DITERMANAL (ORION, Budapest) permet d'effectuer des analyses arbitrales.A l'université technique de Brno de petites tables instruments jumeaux isopériboliques permettant aussi d'effectuer des analyses directes des corps solides ont été réalisés. L'application de thermistors PTC et un dispositif pour l'étalonnage augmentent l'exactitude des mesures.Des méthodes nouvelles nombreuses pour l'analyse des silicates, des pierres calcaires, de l'eau, etc., ont fait l'objet d'études.
, . (, ) (, ). (H, , -). (, ) . , . . , , .相似文献
12.
Back energy transfer reduces the apparent quenching constant, which is an important parameter in the interpretation of energy transfer data. This determination of kinetic results may be erroneous when possible diffusion effects and non-uniform configurational distributions are not taken into account.
, . , .相似文献
13.
S. N. Koshelev E. A. Paukshtis R. S. Sagitullin A. V. Bezrukov A. V. Mashkina 《Reaction Kinetics and Catalysis Letters》1985,27(2):387-391
The effect of reaction conditions on the methylmercaptan formation from dimethylsulfide in H2S catalyzed by -Al2O3 has been studied. The reaction is first order with respect to dimethylsulfide. It has been revealed that the maximum activity in this reaction is observed for the catalysts whose surface contains a large number of aprotonic acid centers and moderate-strength basic sites.
-Al2O3. , . . , , .相似文献
14.
The piperidinolysis of 8-quinolyl-, p-nitrophenyl-, o-, and p-piperidinocarbonylphenyl acetates in acetonitrile and in chlorobenzene was studied at 25°C. The strictly second order kinetic behaviour and the weaks solvent-dependence of the rate of the reaction of o-piperidinocarbonylphenyl acetate indicate anchimeric assistance by the o-amide group, and support the suggestion that amide groups of hydrophobic enzyme active sites may act as general base catalysts.
8--, --, - - 25°C. - - , .相似文献
15.
H. Janicki G. Błotny B. Bator-Sawicka J. Dobrowolski 《Journal of Thermal Analysis and Calorimetry》1976,9(3):401-404
The thermal decompositions of Cr(III) complexes with urea and thiourea were investigated. The courses of the decompositions were found to be anion- and ligand-dependent. Suggestions for a mechanism of decomposition of these complexes are presented. The final product of decomposition of the complexes investigated was chromium(III) oxide (Cr2O3).
Zusammenfassung Die thermische Zersetzung der Komplexe von Cr(III) mit Karbamid und Thiokarbamid wurde untersucht. Der Verlauf der Zersetzung wurde für Anionen- und Liganden-abhängig gefunden. Vorstellungen über eine mechanische Zersetzung dieser Komplexe werden gegeben. Das Endprodukt der Zersetzung der untersuchten Komplexe war jeweils Chrom(III)oxid (Cr2O3).
Résumé On a étudié la décomposition thermique des complexes du chrome(III) avec l'urée et la thiourée. On a trouvé que le processus de la décomposition dépend de l'anion et du ligand. On propose un mode de décomposition mécanique pour ces complexes. Le produit final de la décomposition des complexes étudiés est l'oxyde de chrome(III), Cr2O3.
Cr (111) . , . . (111) (Cr2O3).相似文献
16.
K. Habersberger 《Journal of Thermal Analysis and Calorimetry》1977,12(1):55-58
A short review of the possibilities of application of thermal analysis to the investigation of catalysts is given: analysis of catalysts, investigation of the processes during the preparation of catalysts, desactivation of catalysts, and interaction of reactants or catalytic poisons with the catalysts. Several examples are mentioned.
Zusammenfassung Eine kurze Übersicht über die Möglichkeiten des Einsatzes der Thermoanalyse zur Prüfung von Katalysatoren wird gegeben: Analyse der Katalysatoren, Prüfung der Vorgänge während der Herstellung von Katalysatoren, Inaktivierung von Katalysatoren, Wechselwirkungen zwischen Reagenzien oder Katalysatorengiften und den Katalysatoren. Eine Anzahl von Beispielen wird erwähnt.
Résumé On piésente une rapide vue d'ensemble sur les possibilités d'application de l'analyse thermique à l'étude des catalyseurs: l'analyse des catalyseurs, l'étude des processus ayant lieu lors de la préparation des catalyseurs, la désactivation des catalyseurs, l'interaction de réactifs ou de poisons sur les catalyseurs. Plusieurs exemples sont mentionnés.
. , , —, —, — , . , — . .相似文献
17.
E. M. Sadovskaya S. A. Pokrovskaya Y. A. Yabrov A. A. Ivanov 《Reaction Kinetics and Catalysis Letters》1989,39(2):431-436
Based on numerical analysis of experimental data, the main ideas of the reaction mechanism have been confirmed and kinetic principles of the non-steady=state reaction have been determined.
, .相似文献
18.
The reaction of hydrogen atoms with carbon monoxide has been studied in discharge flow systems with a new method of detection of atoms. The results obtained with tubular and jet stirred open reactors agree with those of other authors working in transient conditions and with more sophisticated techniques.
. , , , .相似文献
19.
E. A. Vishnevetskii S. D. Mikhailenko N. A. Maksimova A. B. Fasman 《Reaction Kinetics and Catalysis Letters》1986,31(2):445-450
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. , , , .相似文献
20.
Cationic rhodium(I) norbornadiene complexes with polystyrene-immobilized imidazole, tetramethylbiimidazole or phosphine ligands in the presence of potassium hydroxide catalyze hydrogen transfer from isopropanol to acetophenone and 1-hexene. [Rh(NBD) (poly-PPh2)2] ClO4 complexes are particularly efficient for the reduction of acetophenone, but slow decomposition to rhodium metal is observed.
(I) , , , 1-. [Rh(NBD) (-PPh2)2]ClO4 , .相似文献