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Some new results concerning complex dynamics in a kinetic model of heterogeneous hydrogen oxidation over metallic catalysts are presented. Relaxation oscillations with a high sensitive dependence on the initial conditions arise in the three-variable system with fast, intermediate and slow variables due to existence of the canard cycles that occur in the one-parameter family of two-variable subsystems. A key feature of the weakly stable dynamics appearance will be successive period doubling bifurcations in which the system behaviour becomes progressively more complex until the attractor appears.

Monolith sorbents/catalysts that have potential in simultaneous removal of H₂S and NH₃ from hot fuel gas were developed. Preparation methodology and composition of supported honeycomb sorbents/catalysts, based on manganese oxides modified by Fe and Cu oxides, have been optimized. Impregnated and washcoated monolith catalysts were tested in ammonia high temperature decomposition and H₂S sorption. Approaches for improving the thermal stability and catalytic activity under reaction conditions are described.

The entire potential energy profile of the catalytic cycle of methanol carbonylation catalyzed by [Rh(CO)₂I₂]^– complex was explored computationally using a gradient-corrected density functional method and polarizable continuum model for accounting of solvent effects. For this purpose, the relative energies of the intermediates and transition states for CH₃I oxidative addition, the CO migratory insertion and the CH₃COI reductive elimination were estimated. Based on calculated energies the lowest-energy reaction path was deduced to be determined by the cis-dicarbonyl species in spite the trans-conformers of 6-coordinated intermediates [RhCH₃(CO)₂I₃]^– and [Rh(CH₃CO)(CO)₂I₃]^– were found to be more stable. The explanation is the lower activation barriers for transformation of cis-conformers to products. The activation barriers for oxidative addition, CO migratory insertion and reductive elimination steps were calculated to be at 135, 40 and 75 kJ/mol, respectively. The first step was found to be the rate-determining. The accounting for solvent effects makes the energy profile smoother and more consistent with experimental reaction profile.

The biotechnological potential of Rhodococcus sp. bacteria for direct selective bioepoxidation of propylene to propylene oxide has been investigated. The kinetics of accumulation of propylene oxide in suspensions of the non-growing bacterial cells has been studied. The effect of propylene oxide produced on biocatalytic activity of Rhodococcus cells has been investigated. The study of bacteria adsorption on various ñarbon-containing inorganic supports has been started to develop efficient adsorbents for Rhodococcus immobilization.

The catalytic activity fluctuations upset the equilibrium in reactions of the hydrogenation of carbon depositions and causes increased coke formation. We propose a method of estimation of the Pt–Re catalysts activity, which allows keeping track of the activity enhancement, and hence provides prolongation of the catalyst service cycle by 20–30 %. The method is based on keeping the catalytic activity at an optimum level using the developed computer system.

The paper concerns the environmentally benign method of catalytic cellulose production by wood delignification over various catalysts using sulfur-free reagents – acetic acid and hydrogen peroxide. The optimum operation conditions (temperature and time of the process, H₂O₂/CH₃COOH and liquor/wood ratios) of abies wood delignification using sulphuric acid as reagent and TiO₂ as catalyst which allow reaching the acceptable yields of cellulosic product with high content of cellulose were selected.

The catalytic system Ru/MgO has been characterized by TEM and XPS in the Ru 3d, Cl 2p and O1s regions. It was shown, that the treatment of the sample with H₂ at 450 °Ñ leads to reduction of supported Ru (III, IV) chloride complexes to Ru metal crystallites of 2–5 nm in size (the surface atomic ratio Ru : Cl of reduced sample is 6.2). The shift of Ru 3d peak (279.5 eV) to lower bond energy (BE) found for Ru/MgO sample as compared with bulk Ru metal (280.2 eV) is proved to be due to the differential charging effect. The value of this effect was estimated by a comparison of the valence band spectrum of supported Ru particles with that of bulk Ru. Taking the differential charging into account, the "true" value BE of Ru 3d_5/2 (280.5 eV) was determined. The shift of Ru 3d peak towards the higher BE values may indicate the electron-withdrawing effect of MgO surface to supported Ru particles.

A change in the ratio between monomeric and polymeric molybdenum species regarding the concentration and pH of the impregnation solutions will probably make a significant effect on the nature and number of active sites of Mo/ZSM-5 catalysts. To provide the control of molybdenum species in solutions, we have studied the dependence of structure of molybdenum species in the initial impregnation solutions of ammonium heptamolybdate on the concentration and pH of these solutions (from electron absorption spectra). When the concentration of solutions is low or pH increases, there are no polymeric molybdenum species. Besides, there is a region where monomeric and polymeric species exist at a time. At higher concentrations or when pH decreases, monomeric species transform almost completely into polymeric species.

In the present work adsorption of NO and coadsorption of NO, CO and O₂ has been investigated by means of thermal desorption spectroscopy (TDS) and temperature programmed reaction (TPR). Influence of adsorbed oxygen on morphology of Pd-nanoparticles as well as Pd(110) plane was studied by the theoretical method of interacting bonds (MIB). It has been shown that adsorption of atomic oxygen induces the morphology changes of Pd-nanocrystals and Pd(110) plane. By analysis of TPR spectra of desorbing N₂ and CO₂ for different NO_ads + CO_ads coverages, we suggest an autocatalytic reaction in an "explosive" way. The addition of oxygen was found to inhibit the process of NO dissociation. Exposure of NO and CO on oxygen pre-adsorbed layer results in appearing of low-temperature peak of CO₂ in TPR spectra at 265 K.

The development of civilization is inevitably connected with the increase of energy consumption. Nowadays the main part of energy is produced through incineration of organic fuel, the products of fuel combustion (CO₂) being discharged into atmosphere. However the ecological problems impelled the world community to intensify their activity in order to decrease CO₂ emission. There is a great number of known chemical reactions, both catalytic and non-catalytic, which bound CO₂ chemically into various products. Specifically, the processes of hydrogen reduction of CO₂ may proceed with the production of methanol, dimethyl ether (DME), methane, light hydrocarbons, or liquid motor fuels. Among these, the processes of motor fuel production on the bi-functional catalysts are most likely to be industrially applied in a large scale. The scientific and technological aspects of the processes of hydrogen reduction of carbon dioxide are considered with regard to CO₂ utilization. The influences of the catalysts composition, pressure, temperature, (H₂–CO₂)/(CO + CO₂) ratio, duration of the test run (up to 1000 h) on the activity and selectivity of the bi-functional catalysts in the synthesis of liquid motor fuels were studied. Depending on the composition of the liquid organic products, utilization of carbon in CO è CO₂ comprised 70 to 90%.