Palladium-containing catalyst based on binder-free granular sulfated zirconium oxide for n-butane isomerization has been investigated. It has been found that Pd content of 0.2–1.0 wt % slightly influences textural characteristics and other physicochemical properties of bifunctional catalysts; however, it determines their activity and selectivity in the reaction studied, with the optimal palladium content being 0.5 wt %. Parameters of the isomerization process have been studied depending on the composition of industrial n-butane fractions. It has been shown that impurities of isobutane, propane, neopentane, isopentane and pentane in an amount of no more than 2% do not exert a effect on isobutane production; nonetheless, the conversion of n-butane and selectivity for isobutane both increase when more pure n-butane fractions are used. It has been found that the process for isobutane production by isomerization of the n-butane fraction under the optimal conditions at H2 /n-C4 = 0.1 and 140–150°C makes it possible to obtain a high isobutane yield (up to 52 wt %) and avoid the undue formation of С1–С3 alkanes.

Part III of this work continues the study of the catalytic properties of new molybdenum carbide based hydroisomerization catalysts, which are resistant to sulfur compounds and allow the synthesis of waxy diesel fuels with the same quality characteristics as those of platinum-containing catalysts. The catalytic properties of such bifunctional catalysts as 7%Mo 2 C/SAPO-31 (LCCH-2) and 7%Mo 2 C/SAPO-11 (LCCH-2-2) in diesel fraction hydroisomerization in the temperature range of 320–400°C are compared. It is shown that LCCH-2 ensures a higher yield of the hydroisomerized diesel fraction with a lower freezing point as compared to LCCH-2-2 at temperatures above 320°C. The ratio between mono- and di-isomers in reaction products is analyzed. It is concluded that SAPO-31 based catalyst is more selective to the formation of terminal monosubstituted alkanes than SAPO-11 based catalyst. The resistance of both catalysts to deactivation with coke deposits (tests over 100 h at 320 and 360°C in hydroisomerization) is studied. It is established that LCCH-2-2 is less resistant to deactivation than LCCH-2. These findings are due to differences in acidity, the degree of uniformity in the distribution of acidic hydrogenating/dehydrogenating sites in the catalysts, and the structural type of their acidic supports.

The aim of this work is to develop a new hydroisomerization catalyst based on molybdenum carbides that is resistant to the influence of sulfur compounds and applicable for the synthesis of low-pour-point diesel fuels that are similar in parameters to the fuel synthesized using platinum-containing catalysts. In the first part of the work, supports with different porous structures and acidities (Beta, ZSM-5, ZSM-12, and SAPO-31) are synthesized and studied. In the second part of the work, bifunctional catalysts prepared by modifying these supports with nanosized molybdenum carbides are studied. All samples contain the same amount of Mo 2 C (10% in terms of the equivalent amount of MoO 3 ). The catalysts are tested using a model isomerization reaction of n -decane. The catalyst based on silicoaluminophosphate ATO (SAPO-31) proves to be the most effective one. In order to optimize its composition, larger batches of samples with different Mo 2 C contents (5, 7 and 10% in terms of the equivalent amount of MoO 3 ) are prepared. The catalytic properties are studied using the hydroisomerization of actual diesel fractions. The optimum content of Mo 2 C (7 wt %) in the bifunctional catalyst is determined.

Hydroisomerization catalysts based on nanosized molybdenum carbides are developed. Such catalysts are resistant to sulfur compounds and can be used for the synthesis of waxy diesel fuels with the same characteristics as on platinum-containing catalysts. In the first part of this work, acidic supports with different types of porous structure and concentrations and strengths of Brønsted acidic sites (e.g., silicoaluminophosphate SAPO-31, zeolite ZSM-12, modified zeolite Beta, and desiliconized zeolite ZSM-5) are synthesized for a new type of catalysts. Their physicochemical properties are studied by means of adsorption, temperature- programmed desorption of ammonia (TPD-NH 3 ), nuclear magnetic resonance (NMR) spectroscopy, and scanning electron microscopy (SEM).

Part 3 of the studies dealt with catalytic properties of the new catalysts based on molylbdenum carbides, resistant to sulfur compounds and providing manufacturing of low pour point diesel fuel with the quality indices identical to those obtained with platinum-containing catalysts. Catalytic properties of bifunctional catalysts 7%Mo2C/SAPO-31 (LCCH-2) and 7%Mo2C/SAPO-11 (LCCH-2-2) for hydroisomerization of diesel fractions were compared at the temperature range between 320 and 400 °C. It was shown that at above 320 °C the catalyst LCCH-2, against LCCCH-2-2, provided the formation of the hydroisomerized diesel fraction at a higher yield and freezing at a lower temperature. Inspection of the data on the ratio of total quantities of monomers and diisomers in the reaction products led to conclude that the former catalyst is more selective than the latter to the formation of terminal monosubstituted alkanes. Studies of the stability of both catalysts to deactivation with coke deposits (100 hour testing at 320 and 360 °C during hydroisomerization) revealed that LCCH-2-2 is less stable to deactivation than LCCH-2. The observed regularities were accounted for by differences in the acidities, degree of homogeneity of distribution of acid and hydrating-dehydrating centers through the catalysts under study, and types of structures of the acid support.

The studies were aimed at the development of hydroisomerization catalysts based on nanosize molybdenum carbides. These catalysts were expected to be resistant to sulfur compounds and applicable for synthesis of low pour point diesel fuels similar in parameters to the fuel synthesized over platinum catalysts. Acidic supports were synthesized for these catalysts; the supports differ by the type of their porous structures, number and strength of Broensted acid sites; these were silicoaluminophasphate SAPO-31, zeolite ZSM-21, modified zeolite Beta, desalicided zeolite ZSM-5. Adsorption methods, TPD of ammonia, NMR, SEM techniques were used for studying physicochemical properties of the supports.

The studies were aimed at the development of hydroisomerization catalysts based on nanosize molybdenum carbides. These catalysts were expected to be resistant to sulfur compounds and applicable for synthesis of low pour point diesel fuels similar in parameters to the fuel synthesized over platinum catalysts. Part I dealt with synthesis and characterization of supports with different porous structures and acidities (Beta, ZSM-5, ZSM-12, SAPO-31). Part 2 of the work was devoted to studies of bifunctional catalysts prepared by modifying these supports with nanosize molybdenum carbides. All the samples bore identical amounts of Mo 2 C (10 % expressed in terms of the equivalent amount of MoO 3 ). The catalysts were tested using a model reaction of isomerization of n -decane. The catalyst based on silicoaluminophosphate ATO (SAPO-31) was most active to isomerization. Larger batches of the catalysts with different Mo 2 C contents (5, 7 and 10 expressed in terms of the equivalent amount of MoO 3 ) were prepared to optimize the composition. The catalytic properties were studied using hydroisomerization of actual diesel fractions. The optimal content of Mo 2 C (7 wt %) in the bifunctional catalyst was determined.

Model low-percentage metal oxide palladium catalysts are prepared from acetate complexes of Pd and Mn to study the nature of the activity and the genesis of nanostructured membrane catalyst Pd-Mn systems. A comprehensive study of the prepared model precursor compounds; specific features of their metal components in gels and oxides; and the genesis of the active component, local structure, and charge state is performed by EXAFS and XANES. Possible versions of structural models for the stabilization of metals on oxide supports aare discussed.

This work is concerned with the study of Au specimens produced by gold deposition on nanosized mixed oxides (alumina, ceria, zirconia) prepared by the sol-gel method using organometallic precursors. According to X-ray absorption near edge structure, extended X-ray absorption fine structure, transmission electron microscopy data, and ultraviolet-visible and X-ray photoelectron spectroscopy measurements, mixed Al-Ce-Zr oxides are quite effective for stabilization of different gold specimens. The samples pre- treated in hydrogen at 150°C are characterized by the presence of gold Au 3+ cations located on the surface in slightly disordered octahedral oxygen coordination. Metallic gold nanoparticles with a size of about 2 nm and gold clusters were found in the samples treated in hydrogen at 300°C.

This work is concerned with the study of Au specimens produced by gold deposition on nanosized mixed oxides (alumina, ceria, zirconia) prepared by the sol-gel method using organometallic precursors. According to X-ray absorption near edge structure, extended X-ray absorption fine structure, transmission electron microscopy data, and ultraviolet-visible and X-ray photoelectron spectroscopy measurements, mixed Al-Ce-Zr oxides are quite effective for stabilization of different gold specimens. The samples pre- treated in hydrogen at 150A degrees C are characterized by the presence of gold Au3+ cations located on the surface in slightly disordered octahedral oxygen coordination. Metallic gold nanoparticles with a size of about 2 nm and gold clusters were found in the samples treated in hydrogen at 300A degrees C.

This work is devoted to a structural study of the finely dispersed nanosized gold species supported on nanosized mixed oxides prepared by the sol–gel method. An analysis of the XANES (Au-L3) spectra has revealed mainly Au3+ cations located on the oxide matrix surface in distorted octahedral coordination for the catalysts reduced at 150°C. For the catalysts reduced at 300°C, a highly distorted metallic gold species has been mainly found, within the method limitation. The synthesized catalysts have also been characterized by transmission electron microscopy (TEM), BET, X-ray diffraction (XRD) and XPS.

A comparative study of conversion of n-octane and n-hexadecane in conditions of BIMF process was performed to follow reaction pathways and to estimate advantages to use heavier distillates for obtaining high-quality fuels. It was found that the conversion of both n-octane and n-hexadecane depends on reaction pressure, and the yield of liquid reaction products is higher in the case of heavier feed. However products of n-octane conversion demonstrate more stable behavior with TOS (Time On Stream). Benzene content is lower in the case of n-hexadecane. A positive effect of heavier hydrocarbons in minimizing dealkylated aromatics content was demonstrated by special experiments.

The new method of the bifunctional catalyst preparation, based oil modification of zeolite catalyst with the Co(III)-Mo(V) oxalato complex, is described. From the catalytic data and the results of XPS studies of the catalyst the conclusion about Co/Mo localization on the particles of Al2O3 binder was drawn.

The possibility of manufacturing high-octane gasolines and winter diesel fuel with a low n-alkane and aromatic hydrocarbon content from high-sulfur petroleum distillates with an endpoint under 350°C in one stage was demonstrated. The octane number of the gasolines is regulated by the mass feedstock space velocity. The catalyst used allows obtaining environmentally clean high-octane gasolines and diesel fuels without additional hydrotreating.

Increasing the exhaustiveness of refining due to depletion of easily refined crude oil resources is basically attained by improving the catalytic systems and revamping the process units, which increases the cost of the processes and in the final analysis, the cost of the finished products.

Catalytic conversion of an oil distillate with the added extra amounts of thiophene over a zeolite catalyst was studied. The rate of the catalyst deactivation was found to increase with the increase in the thiophene concentration in the feed. A possible pathway of the thiophene conversion is discussed.

This chapter contains section titled: Introduction Experimental Results and Discussion Conclusions References

Reversible transformations Ni(IV)↔Ni(II) in alumina and Sibunit supported (Ni,Mo) sulfide catalysts were observed after in situ thermal treatment of catalysts in an X-ray photoelectron spectrometer chamber. The phenomenon is interpreted as a reductive elimination of occluded hydrogen under low pressure and high temperature, and oxidative addition of hydrogen after catalyst treatment with an (H2+H2S) mixture.