Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Investigation of the promotion effect on the sulfide sulfur mobility and on the catalytic activity of hydrotreating Co/Mo/Al2O3 catalysts using35S (1990)
    Springer
    Catalysis letters 6 (1990), S. 157-161 
    Details
    ISSN: 1572-879X
    Keywords: Hydfotreatment ; hydrodesulfurization ; catalysis ; sulfide catalysts ; promoter effect ; radioisotope ; sulfur mobility ; catalytic activity ; thiophene ; cobalt ; molybdenum ; alumina
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Using S the effect of sulfur in Co/Mo/A12O3 catalysts on catalytic activity has been studied. A linear dependency between the amount of sulfur capable of participating in the formation of H2S and the catalytic activity has been established. It has been shown that with increasing the Co content, the overall amount of sulfide sulfur in the catalyst changes negligibly, while the amount of mobile sulfur increases linearly. It has been found that the promoter effects on the two groups of active sites that determine the sulfide sulfur mobility are different.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00774715
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Heterogeneous catalysts in the alkylation of imidazoles (1994)
    Springer
    Chemistry of heterocyclic compounds 30 (1994), S. 547-550 
    Details
    ISSN: 1573-8353
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The reaction of imidazoles with alcohols at 300–400°C was studied in the presence of heterogeneous γ-Al2O3 catalysts and Y zeolites. The major reaction was found to be N-alkylation. This reaction is accompanied by C-alkylation on γ-Al2O3 while the selectivity relative to N-alkylation is close to 100% on zeolite catalysts. The greatest activity with 100% selectivity was found for H zeolite. The alkylation of methanol and ethanol by 2-methylimidazole at 310–320°C gave 1,2-dimethylimidazole in -100% yield and 1-ethyl-2-methylimidazole in 90% yield respectively. The reaction of methanol and imidazole gave 1-methylimidazole in 99% yield. This catalyst displays high stability and capacity for oxidative regeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01169831
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Oxidative dehydrogenation of alkylheteroaromatic compounds 1. Catalysts containing vanadium and molybdenum for the oxidative dehydrogenation of alkylpyridines (1994)
    Springer
    Chemistry of heterocyclic compounds 30 (1994), S. 701-708 
    Details
    ISSN: 1573-8353
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The dehydrogenation of a series of alkylpyrïdines has been studied on vanadium and molybdenum oxide-containing catalysts in the presence of oxygen of the air and sulfur dioxide gas. A dependence was shown of the catalytic and physicochemical properties of the catalysts indicated on their composition and method of preparation. The optimum catalyst composition and the conditions of carrying out the reaction to provide high activity and selectivity when making vinylpyridines were determined. The relative reactivity of the alkylpyridines investigated on dehydrogenation and further oxidation was determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01166312
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Pt/Al2O3 catalysts in the synthesis of nitrogen heterocycles. Catalytic synthesis of pyrazines (1993)
    Springer
    Chemistry of heterocyclic compounds 29 (1993), S. 1308-1315 
    Details
    ISSN: 1573-8353
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A study was carried out on the use of Pt/Al2O2 catalysts in the synthesis of pyrazines via the dehydrogenation of piperazines, dehydrodeamination of diamines, and dehydrocyclocondensation of N-hydroxyalkyldiamines. In contrast to the current hypothesis of the intermediate formation of piperazine in the latter two reactions, evidence was found that these reactions proceed through initial dehydrogenation and the dehydrogenated intermediate then undergoes cyclization. Polyalkylpyrazines, formed by the alkylotion of the pyrazine ring by hydrogenolysis products, are the major side-products in all the reactions studied. Pyrazines may be obtained in high yield and satisfactory selectivity by selecting suitable modifiers, which enhance the dehydrogenation activity of the catalyst and suppress the hydrogenolysis of the C-N bond.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00532031
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Synthesis of 1,4-dioxene from diethylene glycol in the presence of bifunctional copper-containing catalysts. Effect of support on the selectivity of dioxene formation (1996)
    Springer
    Chemistry of heterocyclic compounds 32 (1996), S. 23-29 
    Details
    ISSN: 1573-8353
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract In the synthesis of 1,4-dioxene from diethylene glycol in the presence of a bifunctional copper-containing catalyst, the composition of the byproducts has been studied and the effect of the support on the overall direction of the reactions has been investigated. It has been established that on Cu/SiO 2,1,4-dioxanone is formed together with dioxene, the yield of the former increasing with an increase in the content of copper in the catalyst. This is due to an increase in the dehydrogenating function of the latter. On the more acidic Cu/Al 2O3,1, 4-dioxane is mainly obtained together with, to a lesser degree, methyl-1, 3-dioxolane. This is due to the predominance of dehydration reactions followed by isomerization. Dioxene, dioxane, and methyldioxolane are formed on Cu/HNaY, and the yield of the latter increases with an increase in the degree of acidity (degree of decationization) of the zeolite. It is possible to increase the selectivity of dioxene formation substantially with the use of a catalyst with a moderately acidic zeolite, by varying its copper content and by dilution with water vapor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01169348
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    The mechanisms of the formation of by-products in the catalytic synthesis of C-alkylimidazoles from diamines and carboxylic acids (1993)
    Springer
    Russian chemical bulletin 42 (1993), S. 895-898 
    Details
    ISSN: 1573-9171
    Keywords: C-alkylimidazoles ; platinum-on-alumina catalyst ; 1-ethyl-2-methylimidazole ; 1 -ethyl-2-methylimidazoline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The formation of 1-ethyl-2-methylimidazole (1-Et-2-MI) and 1-ethyl-2-methylimidazoline (1-Et-2-MIN), intermediates in the synthesis of 2-methylimidazole (2-MI) from ethylenediamine (EDA) and AcOH in the presence of a platinum-on-alumina catalyst, was studied. Using CH3 14COOH the incorporation of two acetate units into 1-Et-2-MI and 1-Et-2-MIN molecules was demonstrated. The same products were also obtained on dehydrogenation of 2-methylimidazoline (2-MIN) under mild conditions (220–230 °C). A part of the latter is transformed to N-ethyl ethylendiamine (EEDA) and EDA. These facts indicate that both 1-Et-2-MI and 1-Et-2-MIN result from hydrogenolysis of the imidazoline ring with subsequent ethylation. A reverse reaction, the C5-cyclization of EEDA, was also observed. The formation of 2-MI is favored by increasing temperature.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00698956
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Dehydrogenation of butane-butene mixtures investigated with the aid of C14 (1957)
    Springer
    Russian chemical bulletin 6 (1957), S. 167-175 
    Details
    ISSN: 1573-9171
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary 1. It was shown that in the dehydrogenation of butane-butene mixtures over a chromium oxide catalyst the formation of butadiene proceeds by the dehydrogenation, of butene; practically no direct conversion of butane into butadiene occurs. 2. t was found that the rate constant for the desorption of butene is greater than that for its dehydrogenation, a fact which is important in principle for the theory of dehydrogenational catalysis. 3. esults were obtained which indicate that a reaction of redistribution of hydrogen occurs between butane and butene, consisting in simultaneous hydrogenation of butene and dehydrogenation of butane proceeding together with the general dehydrogenation reaction. This new reaction is on the one hand allied to disproportionation of hydrogen, and on the other to isotopic exchange of hydrogen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01170549
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Mechanism for the aromatization of N-hexane on an alumina-chromium-iron catalyst (1981)
    Springer
    Russian chemical bulletin 30 (1981), S. 1881-1883 
    Details
    ISSN: 1573-9171
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Conclusions 1. The formation of an aromatic hydrocarbon from a paraffin on an alumina-chromium-iron catalyst not containing alkali proceeds through the sequential dehydrogenation of the aliphatic molecule, i.e., through a mechanism which is well known for oxide aromatization catalysts. 2. The contribution of aromatization pathways through the formation of cyclic products in the first reaction steps is either very small or absent completely.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00963413
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Transformations of n-hexane and 1-hexene on aluminum, gallium, and indium oxides (1980)
    Springer
    Russian chemical bulletin 29 (1980), S. 613-616 
    Details
    ISSN: 1573-9171
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Conclusions 1. A study of the transformations of n-hexane and 1-hexene under pulse conditions disclosed that the oxide Al2O3 has a very weak, while Ga2O3, and especially In2O3, have a strong aromatizing (dehydrogenation) and hydrogenation activity, but these are still inferior to the oxide Cr2O3. 2. The studied oxides of the Group III elements catalyze the migration of the double bond in olefins. 3. The aromatization of hexane on Ga2O3 and In2O3 proceeds by the same mechanism as holds for other oxide catalysts for the aromatization of hydrocarbons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00961614
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Study of aromatization of n-hexane on aluminum — Platinum catalyst by method of labeled molecules (1980)
    Springer
    Russian chemical bulletin 29 (1980), S. 616-621 
    Details
    ISSN: 1573-9171
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Conclusions 1. By using the method of labeled molecules it was shown that the aromatization of hexane on the Al-Pt catalyst AP-64 proceeds along two parallel paths: with the intermediate involvement of hexenes and of methylcyclopentane. The direct cyclization of hexane to cyclohexane does not occur. 2. Only half of the total amount of benzene is formed with the involvement of the hexenes and methylcyclopentane, which are desorbed in the gas phase. 3. The theory was expressed that in the presence of an Al-Pt catalyst a substantial portion of the transformations of hydrocarbons occurs on the catalyst without the formed intermediate products escaping into the interior.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00961615
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...