The composition, structure, catalytic activity, and selectivity of alumina-supported cobalt catalysts promoted with ruthenium deposited by different methods were studied. The systems with bimetallic RuCo nanoparticles were studied in the Fischer–Tropsch synthesis. The catalyst containing 13.38 wt

The influence of carbon on the genesis of the active phase of cobalt in aluminum–magnesium spinel supported catalysts on their catalytic properties in the synthesis of hydrocarbons from CO and H2 has been studied. Promotion with carbon was carried out by two independent methods: in the first one, carbon was deposited on a spinel support by thermolysis of glucose followed by the deposition of cobalt; in the second one, the catalyst was prepared by coimpregnation of the support with a solution of cobalt nitrate and glucose followed by thermolysis. The catalysts were characterized by simultaneous thermal analysis in combination with mass spectroscopy of evolved gases, in situ magnetic measurements, low-temperature nitrogen adsorption, and transmission electron microscopy. The modified catalysts showed a significantly higher CO conversion rate (turnover frequency) and selectivity for target liquid hydrocarbons compared to the unpromoted catalyst.

The features of hydrogenation of carbon monoxide and carbon dioxide over the Fe-based Fe/C and FeK/C catalysts were studied. The promotion of the iron-based catalyst on the carbon support with potassium at equal CO2 conversions leads to an increase in the chain growth probability (α) and in a significant increase in the selectivity to C5+ hydrocarbons, including olefins. Carbon dioxide hydrogenation was studied in a wide pressure range. Only CO is formed as a result of CO2 hydrogenation at a pressure of 0.1 MPa and temperatures from 300 to 400 S. An increase in pressure up to 2.0 MPa leads to a deeper hydrogenation of SO2 to saturated and unsaturated hydrocarbons with α = 0.54—0.66. A further pressure increase up to 6.5—8.5 MPa makes it possible to enhance the selectivity to hydrocarbons. A higher value of the chain growth probability (α = 0.78) was obtained over the FeK/C catalyst in the Fischer—Tropsch synthesis.

Iron-containing catalysts promoted with potassium supported on a carbon carrier were prepared by changing the sequence of the introduction of components (iron and potassium) into the carrier (activated carbon) using an impregnation method. After calcination, the catalysts contained hematite and magnetite; in this case, the particle sizes of iron oxides depended on the sequence of the introduction of a potassium promoter. A minimum particle size was observed upon the subsequent introduction of initially potassium from nitrate and then iron. The activation of all of the catalysts in a flow of CO/H2 resulted in the formation of Hägg carbide (Fe5C2). It was shown that the catalyst with the smallest carbide particle size was the most active in the hydrogenation of CO.

Novel nanohybrid materials were prepared by immobilizing Co nanoparticles on a microporous framework MIL-53(Al) as a porous host matrix. The synthesized cobalt-containing materials were characterized by XRD, STEM, and oxygen titration. The catalytic performance of Co@MIL-53(Al) nanohybrids was examined in Fischer-Tropsch synthesis (FTS) for the first time. A higher selectivity to C5+ hydrocarbons and lower selectivity to methane for Co@MIL-53(Al) as compared to conventional Co/Al2O3 were observed.

Рассматриваются особенности синтеза, физико-химические характеристики и специфика работы в восстановительных процессах предложенных нами ранее новых многофункциональных полиметаллических катализаторов. Предшественниками катализаторов являются сложные интерметаллиды 3d-металлов и редкоземельных элементов, получаемые методом самораспространяющегося высокотемпературного синтеза (СВС). Структура катализатора включает каркас из низших интерметаллидов, покрытый сильно разупорядоченной, в значительной мере аморфной, металл-оксидной активной фазой. Эта фаза образует на поверхности двухуровневые наноструктуры ( 10 100 нм) с характерной формой плоских шестигранников. Катализаторы обладают высокой активностью в реакциях глубокого окисления и восстановления (синтез Фишера–Тропша, гидродесульфирование нефтяных фракций), причем в процессах восстановления не требуют предварительной активации.

The synthesis, physicochemical characteristics, and operation of the previously proposed new multifunctional polymetallic catalysts in reduction processes are considered. The complex intermetallides of 3d metals and rare-earth elements, which are obtained by self-propagating high-temperature synthesis (SHS), are catalyst precursors. The catalyst structure includes a framework of lower intermetallic compounds covered with a strongly disordered highly amorphous metal oxide active phase. This phase forms two-level nanostructures (~10–100 nm) with a characteristic shape of flat hexahedrons on the surface. The catalysts possess high activity in the reactions of deep oxidation and reduction (the Fischer–Tropsch synthesis and the hydrodesulfurization of petroleum fractions); moreover, they do not require preliminary activation in the reduction processes.

Toluene hydrogenation was investigated over different platinum-titania catalysts. It was found that the form of kinetic equation of the reaction does not depend on the modifications of titania (rutile, anatase) but the catalyst activity is different. The catalyst reduction at temperature higher than 300oC leads to strong metal-support interaction (SMSI) which is manifested in a decrease of the reaction rate.