Kinetics and mechanism of the production of higher olefins from stearic acid in the presence of an alumina-supported nickel sulfide catalyst

A nickel sulfide catalyst which efficient in the decarbonylation of fatty acids to olefins and dienes has been obtained for the first time by treating alumina-supported nickel sulfate with hydrogen, and its properties have been studied. In its presence, the olefin selectivity of the reaction can exceed 90%. The kinetics of stearic acid deoxygenation to heptadecenes has been investigated, a kinetic model has been constructed, and a mechanism has been proposed for the reaction over this catalyst. Olefin oligomerization is the dominant side reaction. Kinetic evidence for the catalytic inhibition of oligomerization by nickel hydrides formed on the catalyst has been obtained. The compositions of active site–reactant adsorption complexes have been discussed.     

The influence of the support on activity and selectivity of nickel sulfide catalysts in the decarbonylation of stearic acid to heptadecenes

The influence of the support nature on the performance of nickel sulfide catalyst in the decarbonylation of stearic acid to heptadecenes was investigated. The catalyst supported on silica demonstrated higher activity and selectivity in comparison with the catalyst on γ-Al₂O₃ used as a reference. The reaction schemes over these catalysts are nearly the same; however, the contributions from the side reactions of hydrogenation and oligomerization are reasonably different. Introduction of the products of decarbonylation (CO and water vapor) decreases the stearic acid conversion; and in the case of the catalyst supported on silica, the addition of CO strongly reduces the rate of hydrogenation of heptadecenes. The reasons for the observed differences were discussed. It was suggested that the dispersion of the nickel component as well as the nature of support acidity played a significant role.     

Catalytic syntheses of polycyclic compounds based on norbornadiene in the presence of nickel complexes: V. Codimerization of norbornadiene and methyl vinyl ketone on heterogenized nickel catalysts

A new heterogenized nickel catalyst was developed for the codimerization of norbornadiene and methyl vinyl ketone. This catalyst considerably improved the performance characteristics of the process (selectivity, specific activity, and operating time), as compared with available analogs. A thermogravimetric study of the formation of the active component of the catalyst was performed. Factors affecting the selectivity and productivity of the process were determined.     

Temperature dependence of the rate of rapid reactions of proton transfer in aqueous solution

Conclusions The kinetics of the reactions of proton transfer from aqua-complexes of transition metals to the dianion of dibromocresolsulfophthalein in aqueous solution at temperatures from 8 to 50° was studied by the temperature jump method.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 299–305, February, 1974.Deceased.     

Kinetics and Mechanism of Thermal Decomposition of Bis(η3-Allyl)Nickel Complexes

Kinetics and Catalysis - The kinetics of thermal decomposition of bis(η3-allyl) nickel complexes in various media is studied. The specific features of the mechanism are determined, including...     

Effect of promotion of nickel sulfide catalyst with silver on kinetics of decarbonilation of stearic acid

Russian Chemical Bulletin - The kinetics of liquid-phase decarbonylation of stearic acid in n-dodecane on γ-Al2O3 supported nickel sulfide catalyst promoted with silver was experimentally...     

The Mechanism and Kinetic Models of the Catalytic Oxidation of Ethylene by <Emphasis Type="Italic">p</Emphasis>-Benzoquinone in Aqueous–Acetonitrile Solutions of Pd(II) Cationic Complexes

A kinetic study of ethylene oxidation to acetaldehyde by p-benzoquinone in the Pd(OAc)₂–HClO₄?LiClO₄–CH₃CN–H₂O system has been carried out under conditions when palladium(II) cationic complexes exist at a molar fraction of water of 0.67 and 30°С. For a reaction that mostly lead to the formation ofPd(CH₃CN)(H₂O) ₃ ²⁺ two-route mechanism and a kinetic model have been proposed that describe adequately the experimental dependence of the reaction initial rate on the concentration of p-benzoquinone, HClO₄, and palladium. The model takes into account previous findings on the H₂O/D₂O and C₂H₄/C₂D₄ kinetic isotope effects and the important role of Pd(0) quinone complexes.