共查询到20条相似文献,搜索用时 812 毫秒
1.
N. I. Kuznetsova A. S. Lisitsyn V. A. Likholobov 《Reaction Kinetics and Catalysis Letters》1989,38(1):205-208
Conditions are found for the preparation of Pt catalysts providing the formation of epoxy-derivative in the reaction of cyclohexene with an O2/H2 mixture.
Pt .相似文献
2.
M. A. Fedotov R. I. Maksimovskaya L. P. Kazanskii 《Reaction Kinetics and Catalysis Letters》1981,16(2-3):185-189
17O,51V and31P NMR studies indicate that the anion structure of sodium vanadophosphate in an aqueous solution is close to that in crystals of the (CN3H6)8HPV14O42 7H2O salt.
17O,51V,31P , (CN3H6)8HPV14O42 7H2O.相似文献
3.
The sulfur resistance of Pt–Re/Al2O3-ZSM-5 catalyst has been investigated for normal heptane reforming. It was found that while sulfur acts as a poison for Pt–Re/Al2O3, it can play an important role in activity maintenance and aromatics production when ZSM-5 zeolite is present.
Pt–Re/Al2O3-ZSM-5 -. , , Pt–Re/Al2O3, ZSM-5.相似文献
4.
N. M. Vitkovskaya V. G. Bernshtein F. K. Schmidt 《Reaction Kinetics and Catalysis Letters》1986,31(1):167-172
[Cu(-C2H2)2]+, [Cu(-CCH2)2]+ and [Cu(-C2H2) (-CCH2]+ complexes have been studied by the ab initio double-zeta basis set method. It has been established that all calculated compounds are stable to decomposition into two C2H2 molecules and Cu+ cation and into one C2H2 molecules and the respective monocomplex. Calculation results suggest the possibility of intramolecular acetylene-vinylidene rearrangement in the coordination sphere of Cu+.
ab initio : [Cu(-C2H2)2]+, [Cu(-CCH2)2]+, [Cu(-C2H2) (-CCH2)]+. C2H2 Cu+ C2H2 . - Cu+.相似文献
5.
The activity of vanadia/titania catalysts in CO oxidation has been tested and found to be of the same order as that observed for unsupported vanadia; the simultaneous presence of vanadium-sodium compounds cancels the activity, probably because of the elimination of labile V=0 species at surface defects.
V2O5/TiO2 CO, V2O5; - , , V=0 .相似文献
6.
I. Ferino B. Marongiu S. Torrazza L. Forni 《Reaction Kinetics and Catalysis Letters》1980,15(1):95-101
Rh catalysts supported on different -aluminas were prepared and tested under identical conditions. Both catalytic activity and selectivity seem to depend on the surface concentration of acid sites. The bifunctional character of the catalyst and the role played by the support in activating the reactants are confirmed.
, - . , . , .相似文献
7.
Desorption of hydrogen liberated in the process of water decomposition on bimetallic catalysts (3% Ir–Fe/Al2O3) at linear temperature growth was observed. In the case of iridium the amounts of desorbing hydrogen are relatively small, whereas for iron they are many times greater.
, 3% Ir–Fe/Al2O3 . , , .相似文献
8.
J. A. Lercher 《Reaction Kinetics and Catalysis Letters》1982,20(3-4):409-413
Mixed oxides of alumina and magnesia were characterized by an IR study of pyridine adsorption. Three different Lewis acid sites, but no Brönsted acid sites were detected. The strongest adsorption sites are attributed to Al3+ cations of the alumina phase (1455 cm–1), the weaker Lewis acid sites were assumed to be due to cations of the MgAl2O4 phase (1449–1443 cm–1) and the MgO phase (1440–1438 cm–1).
. , , . Al+3 (1455 –1), MgAl2O4 (1443 –1) MgO (1438 –1).相似文献
9.
P. B. Jadkar S. P. Gupte R. V. Chaudhari 《Reaction Kinetics and Catalysis Letters》1985,27(1):195-200
The effect of equilibrium concentration on adsorption has been studied at different temperatures and the nature of isotherms is discussed. For the formaldehyde-Cu2C2-silica gel system, Freundlich type equations describe the data satisfactorily.
. . -Cu2C2- .相似文献
10.
N. S. Golubev 《Reaction Kinetics and Catalysis Letters》1977,7(2):225-228
The kinetics of hydrogen bond dissociation and formation in solution has been studied by a lineshape analysis of the1H NMR signals of the proton donor (CF3COOH) and proton acceptor (DMF) between –100 and –170°C. It has been found that proton exchange is much slower than molecular exchange and it does not affect the lineshape. A stepwise mechanism has been confirmed.
( ) () — –100°–170°C. , . .相似文献
11.
P. P. Mardilovich V. M. Zelenkovskii G. N. Lysenko A. I. Trokhimetz G. M. Zhidomirov 《Reaction Kinetics and Catalysis Letters》1988,36(1):107-112
A quantum-chemical analysis of the models for geminal OH groups of Al2O3 and of the processes of their dehydroxylation with further dissociative chemisorption of hydrogen has been carried out. Calculations were performed by the SCF MO LCAO method using STO-3G basis set in terms of the cluster approach.
OH- Al2O3 . , STO-3G .相似文献
12.
J. M. Libre Y. Barbaux B. Grzybowska J. P. Bonnelle 《Reaction Kinetics and Catalysis Letters》1982,20(3-4):249-254
Bi2Mo3O12 is a selective oxidation catalyst of propylene into acrolein. Surface potential measurements proved the presence of an equilibrium between gaseous oxygen and the O2– species adsorbed on the surface of the catalyst, under oxygen atmosphere, in the range 538K–673K. This is in accordance with the fact that O2– is a selective oxidation species. An oxygen adsorption mechanism is also discussed.
Bi2Mo3O12 . O–2, , 538–613 . , O–2 . .相似文献
13.
D. Ouafi F. Maugé J. C. Duchet J. C. Lavalley 《Reaction Kinetics and Catalysis Letters》1989,38(1):95-101
IR spectroscopy has been used to follow the transformation at different temperatures of piperidine chemisorbed on oxidic or sulfided Ni–W/Al2O3 catalysts. Formation of an intermediate species, possibly tetrahydropyridine, and pyridine is evidenced. Their formation temperature on the sulfided samples accounts for the catalyst activity in pyridine hydrogenation under H2 pressure.
This work was supported by the Groupement scientifique Hydrotraitement catalytique (CNRS-IFP, TOTAL. ELF). 相似文献
- , Ni–W/Al2O3, . , , . .
This work was supported by the Groupement scientifique Hydrotraitement catalytique (CNRS-IFP, TOTAL. ELF). 相似文献
14.
A. A. Mantashyan V. A. Martirosyan N. Z. Yedigaryan G. Ts. Varderesyan 《Reaction Kinetics and Catalysis Letters》1986,31(2):333-336
It has been established that the formation of iron chlorides in chain gas-phase reaction of methane chlorination is observed starting with T650 K. At Cl2:CH4=4:1, Fe2O3 is transformed to FeCl3. With increasing methane concentration (Cl2:CH4=1:1), besides FeCl3, FeCl2 is also formed. Kinetic regularities of the reaction have been studied at 600–1200 for both gaseous mixtures.
, 650 . : 41, Fe2O3 FeCl3. (Cl2CH4=11) , FeCl3 FeCl2. 600–1200 -.相似文献
15.
M. S. Climent J. M. Marinas J. V. Sinisterra 《Reaction Kinetics and Catalysis Letters》1987,34(1):201-206
The oxidation of benzyl halides by DMSO in presence of barium hydroxide as catalyst in the heterogeneous phase is described. The reaction is optimized. The influence of halide and benzyl halide ring substituent on the yield is discussed. The mechanism for the heterogeneous process is discussed.
, . . . .相似文献
16.
N. M. Ostrovskii L. A. Karpova V. K. Duplyakin 《Reaction Kinetics and Catalysis Letters》1984,26(3-4):279-284
Catalysts with nonuniform distribution of the catalytically active component (Pt) over their porous support (Al2O3) have been studied. A nonuniform activity distribution changes not only the reaction rate but also the kinetics can be different on these catalysts.
(Pt) (Al2O3). , , .相似文献
17.
CO hydrogenation on cobalt-rutile and cobalt-anatase catalysts with various amounts of cobalt at 480–570 K has been studied. C1–C15 hydrocarbons are formed on cobalt-rutile catalysts at 478–523 K. During the initial period of catalyst operation a counterclockwise hysteresis is observed. Cobalt-anatase catalysts remain inactive up to 670 K.
CO - - - 480–570 . - 478–523 C1–C15. . - 670 .相似文献
18.
The effect of pressure on the rates of product formation in n-heptane conversion on Pt/Al2O3 has been studied at 490 °C over the pressure range of 10–50 atm. It has been shown that the rate of isomerization is practically independent of pressure, and the dependence of the rates of dehydrocyclization and hydrocracking on pressure is described by simple kinetic equations. The reaction order of dehydrocyclization with respect to hydrogen tends to –2.0 at high pressures.
- 10–50 490°C. , , . –2,0.相似文献
19.
V. Cortés Corberán G. Kremenic L. González Tejuca 《Reaction Kinetics and Catalysis Letters》1988,36(1):235-240
The effect of UO3 on the acidity of MoO3–UO3/SiO2 catalysts has been studied by means of infrared spectroscopy of adsorbed pyridine. The surface acidity exhibited a maximum for the same U/(U+Mo) atomic ratio (=0.11) that yielded a maximum in total conversion for isobutene oxidation. The catalytic properties for oxidation are discussed in terms of the acidic properties of the samples.
UO3 MoO3–UO3/SiO2 . U/(U+Mo)=0,11, . , .相似文献
20.
V. Kh. Fedotov B. V. Alekseev N. I. Koltsov 《Reaction Kinetics and Catalysis Letters》1985,29(1):71-77
The conditions for dead zone formation in the central part of a porous catalyst grain during the joint process of a reaction with slightly nonmonotonic kinetics and internal diffusion have been established. Relationships for determining the grain sizes responsible for this zone formation are suggested.
, , .相似文献