L. A. Isupova, V. A. Sadykov, S. V. Tsybulya, G. S. Litvak, G. N. Kryukova, E. B. Burgina and A.V. Golovin
G. K. Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Pr. Akademika Lavrentyeva 5, Novosibirsk 630090 (Russia), E-mail: isupova@catalysis.nsk.su
Страницы: 89-100
X-ray, TA, IRS, TEM and BET techniques were used to study the effect of mechanical treatment in a centrifugal planetary ball mill EI 2´150 and in a continuously operating vibration ball mill VCM-25 on physicochemical properties of powdered iron oxide of different prehistory, as well as on the properties of produced granulated supports and catalysts. The influence of structure-forming additives and electrolyte was discussed. The influence of the method used for introduction of the active component on the catalyst properties for complete oxidation of butane and CO was established.
I.В V.В Koptyug1, A.В V.В Kulikov2, A.В A.В Lysova1,2,3, V.В A.В Kirillov2, V.В N.В Parmon2 and R.В Z.В Sagdeev1 1International Tomography Center, Siberian Branch of the Russian Academy of Sciences, Ul. Institutskaya 3A, Novosibirsk 630090 (Russia), E-mail: koptyug@tomo.nsc.ru 2G. K. Boreskov Institute of Catalysis, Siberan Branch of the Russian Academy of Sciences, Pr. Akademika Lavrentyeva 5, Novosibirsk 630090 (Russia), 3Novosibirsk State University, Ul. Pirogova 2, Novosibirsk 630090 (Russia)
Страницы: 109-116
The NMR microimaging is used for the first time as an in situ method to study two model three-phase heterogeneous catalytic reactions with strong exothermicity. It is shown for the α-methylstyrene hydrogenation that in the course of the reaction, two domains coexist inside the catalyst grain which differ in the liquid phase content. The 2D maps of the liquid distribution in the course of this reaction are obtained. The reaction of the hydrogen peroxide decomposition at moderate activity of the catalyst and the H2O2 concentrations in the range of (0.03–3) M is shown to occur only in a thin layer near the catalyst surface. The influence of the medium inhomogeneity on the behaviour of the Belousov – Zhabotinsky chemical oscillator reaction is investigated as well.
R. A.В Kozlovskiy1, V. F.В Shvets1, A. V.В Koustov1, L. E.В Kitaev2, V. V.В Yushchenko2, V. V.В Kriventsov3, D. I.В Kochubey3 and M. V.В Tsodikov4 1D. I. Mendeleev University of Chemical Technology of Russia, Miusskaya Pl. 9, Moscow 125047 (Russia), E-mail: kra@muctr.edu.ru 2M. V. Lomonosov Moscow State University, Chemical Department, Vorobyovy Gory, Moscow 119899 (Russia), 3G. K. Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Pr. Akademika Lavrentyeva 5, Novosibirsk 630090 (Russia), 4A. V. Topchiev Institute of Petrochemical Synthesis, the Russian Academy of Sciences, Leninskii prospect 29, Moscow 117912 (Russia)
Страницы: 123-130
Relationship of structure and surface properties of modified titanium dioxides, prepared by alkoxide method using derivatives of phosphoric acid as precursors, with their catalytic performance in the reaction of ethylene glycol ethoxylation was investigated. It was found, that such catalysts are mono-phase, nanocluster ones with anatase structure, and have uniform narrow pore distribution. Catalysts prepared using the amidophosphite precursors provide high catalytic activity due to the high surface acidity, and high selectivity of diethylene glycol formation due to the "sieve effect" and concert acid-base mechanism of ethylene oxide addition.
G. G. Kuvshinov, D. G. Kuvshinov and A. M. Glushenkov
G. K. Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Pr. Akademika Lavrentyeva 5, Novosibirsk 630090 (Russia), E-mail: ggk@catalysis.nsk.su
Страницы: 135-140
Experimental studies were focused on the feasibility of utilization of hydrocarbons diluted with inert gases (such as associated oil gases) during the synthesis of nanofibrous carbon. The carbon yield and catalyst lifetime were studied regarding the initial reaction mixture parameters. Varying the composition of the initial gas mixture, it is possible to control textural characteristics of the resulting carbon product.
A. A. Lamberov1, R. G.В Romanova2, I. G.В Shmelev2, E. Yu.В Sitnikova1 and S. R.В Egorova2 1Kazan' Chemical Research Institute, Sibirskiy trakt 27, Kazan' 420029 (Russia), E-mail: segorova@rambler.ru 2Kazan' State Technological University, Ul. K. Marxa 68, Kazan' 420015 (Russia), E-mail: rrg@kstu.ru
Страницы: 149-154
The influence of porous structure and surface acid-base properties of γ-Al2O3, prepared by means of aluminate-nitrate and electrochemical methods, on its catalytic activity in the process of α-phenylethanol dehydratation has been studied. It was shown, that activity of catalyst depends on the predominating diameter of pores. The methods of changing the porous structure of γ-Al2O3 with the purpose of increasing its catalytic activity were considered. Thermal or hydrothermal treatment of active aluminium oxide allows to obtain the porous structure, providing the maximum activity of catalyst in the process of α-phenylethanol dehydratation. It was also shown, that conversion of α-phenylethanol and selectivity are determined by the surface concentrations of Broensted and Lewis acid centres. The rate of catalyst deactivation (coke formation) is proportional to the concentration of base centres. The influence of content of sodium cations on the acid-base properties and activity of catalyst was determined. Purification of used γ-Al2O3 from sodium cations results in the catalyst, having the maximum catalytic activity.
G. D. MALCHIKOV1, N. I. TIMOFEEV2, V. I. BOGDANOV2, E. N. TUPIKOVA1 and N. E. GORYAINOVA1 1S. P. Korolev Samara State Aerospace University, Moskovskoye shosse 34a, Samara 443086 (Russia) 2Yekaterinburg Non-Ferrous Metals Processing Plant, Pr. Lenina 8, Yekaterinburg 620014 (Russia), E-mail: chem@ssau.ru
Страницы: 161-166
The metal (stainless steel) porous "metal-rubber" monolith-supported Pt, Pd, Pt–Rh and Pd–Rh catalysts are tested in the process of complete oxidation of hydrocarbons. At stoichiometric and higher oxygen content practically complete conversion of model hydrocarbon occurred at 380 °C on all catalysts. At these temperatures the catalysts work in outward diffusive area. At the oxidant to fuel ratio lower than stoichiometric the maximal conversion of hydrocarbon is reached at lower temperatures (250 °Ñ). In complete hydrocarbon oxidation steady work of platinum catalyst is possible, if the content of sulphur in hydrocarbon does not exceed 0.3 % mass. These catalysts may be used for preparing a gas sample in oxygen sensors.
A. V. Matveev, E. I. Latkin, V. I. Elokhin and V. V. Gorodetskii
G. K. Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Pr. Akademika Lavrentyeva 5, Novosibirsk 630090 (Russia), E-mail: elokhin@catalysis.nsk.su
Страницы: 173-180
The modelling of self-oscillations and surface autowaves in CO oxidation reaction over Pd(110) has been carried out by means of the Monte-Carlo technique. The synchronous oscillations of the reaction rate and surface coverages are exhibited within the range of the suggested model parameters (under the conditions very close to the experimental observations). The dependencies of the simulation results on the lattice size and on the diffusion intensity have been studied. It has been established that the adsorbed CO diffusion anisotropy does not influence the oscillation kinetics but leads to the appearance of the propagating reaction fronts on the palladium surface elliptically stretched along the [110] direction in close agreement with the known experimental data.
T. P. Minyukova, N. V. Shtertser, L. P. Davydova, I. I. Simentsova, A. V. Khasin and T. M. Yurieva
G. K. Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Pr. Akademika Lavrentyeva 5, Novosibirsk 630090 (Russia), E-mail: min@catalysis.nsk.su
Страницы: 189-196
The influence of the structure and composition of precursor (which is used as support after treatment) and the structure of copper particles formed in the course of activation of copper containing catalysts by hydrogen on their catalytic properties in methanol dehydrogenation and reactivity towards hydrogen adsorption has been studied. The reactivity of catalyst towards hydrogen adsorption was investigated by means of Thermal Desorption Spectroscopy (TDS). Two catalysts preserving the structure of their precursor-oxide after reduction (CuZnSi and CuCr) and having strong bonds of metal particles with the surface are characterized by hydrogen adsorption at elevated temperatures. This type of adsorption is not observed for usual unsupported metal copper and for two other catalysts Cu/SiO2 and Cu/Cr2O3. Methanol dehydrogenation proceeds via successive reactions 2CH3OH = CH3OOCH + 2H2 (I) and CH3OOCH = 2CO + 2H2 (II). The catalyst activity in reaction (II) greatly depends on the state of metal copper in the catalyst. It was assumed that catalyst activity in methyl-formate conversion to CO and H2 and, hence, the selectivity of methanol dehydrogenation in respect to methylformate at moderate methanol conversion depends on the character of interaction between metal copper particles and catalyst oxide surface, which is determined by the composition and structure of oxide precursor.
A. V. Nartova and R. I. Kvon
G. K. Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Pr. Akademika Lavrentyeva 5, Novosibirsk 630090 (Russia), E-mail: nartova@catalysis.nsk.su
Страницы: 209-214
Combined XPS and ex situ STM study of the specially prepared model supported silver catalysts was performed. The drastic difference in the Ag particle shape, size distribution and spreading over the support surface were observed for alumina support as compared with pyrographite one. This effect emphasizes the important influence of the substrate nature on the morphology and surface mobility of the supported metal particles
A mathematical model is presented, which simulates the oscillatory behaviour reported for the N2O+H2 reaction over Ir (110) surface. The model describes successfully the very narrow temperature range for the appearance of oscillations and the properties of oscillations including their period and the waveform. The presented model also can simulate the phase shift, between the maxima of H2O and N2 production rates, which has been detected experimentally. It is demonstrated, that this unusual phase shift between production rates of two reaction products is closely connected with the character of lateral interactions in the adlayer.