Том 58, № 2 (2017)

New norbornene-type monomers containing covalently bound C60 fullerene have been obtained. In the presence of the 1st generation Grubbs catalyst [(PCy₃)₂Cl₂RuCHPh] (Cy is cyclohexyl), these monomers smoothly undergo homopolymerization and copolymerization with parent fullerene-free monomers. The homopolymers are insoluble in common organic solvents, while the copolymers obtained at different molar ratios to their fullerene-free analogues are very soluble in organic solvents and can be suitable for the preparation of thin films.

The kinetic curves and rates of bulk radical–coordination polymerization of methyl methacrylate initiated by the benzoyl peroxide–ferrocene system at 293–373 K, initial benzoyl peroxide concentrations of 10^–4–10^–1 mol/L, and a constant initial ferrocene concentration of 10^–3 mol/L have been calculated using a mathematical model in which the process is considered from the standpoint of formal kinetics. The calculations have demonstrated that, at low methyl methacrylate conversions, ferrocene catalyzes the process at any benzoyl peroxide concentration; at medium and high methyl methacrylate conversions, deficient amounts of ferrocene with respect to benzoyl catalyze the process as well, while excess ferrocene inhibits the process. The observed effect is explained by the specific ferrocene–benzoyl peroxide interaction, which, depending on the ferrocene: benzoyl peroxide ratio, either increases or decreases the concentration of radicals in the reaction mass.

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.

Pt-based catalysts cannot be used permanently for the diesel after-treatment system because the catalytic activity is decreased due to coarsening of Pt particles at high temperature of the exhaust gas. In this study, to prevent Pt-based catalyst from deactivation, Nd was added to the Pt/SiO₂ catalyst, and the effect of the Nd addition on the catalytic activity was investigated. The Pt/SiO₂ catalyst showed a high catalytic activity for the oxidation of NO but was severely deactivated after the fast thermal aging process. Pt crystallite size was increased and some Pt particles were buried in the SiO₂ pore during the fast thermal aging process, which led to the decrease of catalytic activity. Nd-added Pt/SiO₂ catalyst showed lower activity than Pt/SiO₂ catalyst, but Pt–Nd/SiO₂ catalyst maintained its catalytic activity after fast thermal aging process. It can be postulated that a stable Nd silicate, on which Pt particle is placed, protects SiO₂ pores from destruction and so the number of the catalytically active sites remains nearly unchanged. As a result the Pt–Nd/SiO₂ catalyst maintained its catalytic activity after fast thermal aging process.

A systematic study of the kinetics of the low-temperature oxidation of carbon monoxide with oxygen on a PdCl₂–CuCl₂/γ-Al₂O₃ supported catalyst was carried out over a wide range of the partial pressures of oxygen, water, and CO in order to test hypotheses on the reaction mechanism. It was shown that, as the temperature was increased from 20 to 38°C, rate of formation of CO₂ decreased and the apparent activation energy was about–40 kJ/mol. The hypotheses of different degrees of complexity concerning the reaction mechanism were formulated based on physicochemical data and a Langmuir–Hinshelwood model. Mechanisms in which carbon dioxide is formed on the interaction of the surface Pd(I) and Pd(II) complexes that include carbon monoxide and water with the surface complex of Cu(I) that coordinates oxygen were recognized as the most probable.

It has been demonstrated by quantitative spectrokinetic measurements that, on the surface of zirconia stabilized as a tetragonal phase, the rate-limiting step of the selective catalytic reduction of nitrogen oxides (SCR of NO_x) with propylene is the interaction of surface nitrates with C₃H₆ yielding organic nitro compounds. It is hypothesized that propylene reacts not with the nitrates themselves but with the activated complex NO₂^ads whose structure is intermediate between the structures of the monodentate NO₃⁻ and NO₂ species. Deep C₃H₆ oxidation exerts an adverse effect on the rate of the SCR of NO_x with propylene, and the interaction between O₂ and NO, which yields NO₂ and NO₃⁻ stimulates further nitrogen reduction to N₂. The effect of the reaction between oxygen and O₂N−C_nH_m on the NO_x reduction rate is variable and is determined by the C₃H₆/NO_x ratio. A generalized scheme of the SCR of NO_x with propylene on the surface of ZrO₂ partially stabilized as a tetragonal phase has been developed by comparing experimental data of this study and data available from the literature.