Aleksey N. Salanov

Honeycomb catalysts for clean-up of diesel exhausts based upon the anodic-spark oxidized aluminum foil

Abstract The technology of the aluminum foil anodic spark oxidation in the water-based electrolytes has been applied to form strongly adhering protective alumina layer at the surface. Basic features of the oxidation were studied by SEM and XRD. Secondary supports, promoters and modifiers including rare-earth elements were used to increase the thermal stability of these composites up to 900°C. These materials were assembled as thin wall honeycomb supports loaded with a number of active components. The catalysts were tested in the reactions of CO and CHx oxidation, NOx selective reduction by hydrocarbons and demonstrated a high performance and a low pressure drop at high space velocities. City diesel buses field tests of converters equipped with those catalysts demonstrated their high and stable performance in clean-up of exhausts from SOF, CO, gaseous hydrocarbons and NOx.

Catalytic synthesis of carbon nanostructures from polymer precursors

Abstract Carbon nanostructures were prepared by decomposition of polyethylene and polyvinyl alcohol using an iron catalyst at 600–750°C under a nitrogen flow. Heating a uniform distribution of catalyst particles in the polymer bulk to 600°C under flowing nitrogen led to the formation of amorphous carbon incorporating uniformly distributed catalyst particles. Subsequent heating of the samples to 750°C in a nitrogen flow led to the catalytic graphitization of the amorphous carbon matrix with the formation of different carbon nanostructures, i.e. carbon nanotubes. The mechanism of the formation of the obtained carbon nanostructures is discussed.

CrAl alloy-based cermet monolith with polymodal pore structure for partial oxidation of methane to synthesis gas

The main stages of the CrAl alloy-based monoliths preparation from the Al and Cr powders through mechanical alloying, hydrothernal treatment and calcination have been described. The textural, mechanical and catalytic properties in the partial oxidation of methane on the monolithic cermets are presented.

Design of Al2O3/CoAlO/CoAl Porous Ceramometal for Multiple Applications as Catalytic Supports

Porous ceramometal Al2O3/CoAlO/CoAl was studied by set of physicochemical techniques such as XRD, SEM, internal field 59Co and 27Al MAS NMR, and porosity measurements. They revealed the cermet containing three parts. First, cobalt-free large porous alumina particles which surrounded by the second oxide part representing spinel CoxAl3-xO4 (x=1,2,3) oxides. And third, oxygen-free metallic part consists of cobalt metal particles covered by Co-Al oxide protecting the metallic part from oxidation. Porosity measurements ascertained high porosity (60%) and good SSA (122 m2/g). Also the enhanced adsorption of microwaves due to metallic particles randomly distributed in oxides was found.

Synthesis of alumina through hydrothermal oxidation of aluminum powder conjugated with surfactant-directed oriented growth

Sergey F. Tikhov, Yulia V. Potapova, Vladislav A. Sadykov, Vladimir B. Fenelonov, Ivan V. Yudaev, Olga B. Lapina, Aleksey N. Salanov, Vladimir I. Zaikovkii, Galina S. Litvak Addresses for Correspondence: S.F.Tikhov, Boreskov Institute of Catalysis, Av.Lavrentieva,5, Novosibirsk, 630090. Russia; tikhov@catalysis.nsk.su; Tel: 007 383 3308764; Fax: 007 383 3308056

Ceramic matrix composites prepared from CoAl powders

Multiscale structure of two CoxAlyOz cermets was examined by a combination of XRD, SEM coupled with EDX, NMR (59Co; 27Al), and textural measurements. A strong CoAlO/CoAl cermet monolith prepared by mechanical alloying of Co and Al powders followed by hydrothermal treatment and calcination in air comprised two parts: the metal core consisting of Co and a Co–Al alloy, and the outer oxide matrix including a mixture of CoxAl3–xO4 spinel and cobalt oxides. The two parts were separated by the alumina interface protecting the metal core against the oxidation. Al2O3/CoAlO/CoAl cermet prepared by mixing the Co–Al mechanically alloyed product and pure aluminum hydroxide with subsequent hydrothermal treatment and calcination in air consisted of three main parts: (i) large cobalt-free porous alumina (ii) surrounded by CoxAl3–xO4 spinel oxides, and (iii) the inner core containing pure Co metal particles covered with the Co–Al alloy. A random distribution of metal particles in the oxide matrix provided an enhanced microwave absorption. A developed porosity ensured a high activity of the catalyst prepared from the porous cermet in the hexane dehydrogenation under microwave heating.

Catalytic combustion of brown coal particulates over ceramometal honeycomb catalyst

Abstract Catalytic combustion of brown coal particulates over CuO/Al2O3/FeAlO/ FeAl honeycomb ceramometal catalyst in the fluidized bed regime with the sand as a heat transfer material has been studied during 100 hours at 973-1023 K. The catalyst before and after tests has been analyzed. The coal conversion in the presence of cermet catalyst was found to be in the range of 97.8-98.5% while without catalyst it was lower (91.2-94.6%). A substantial decrease of CO, NOx and SO2 emissions in catalytic combustion was also demonstrated.

Zrfe intermetallides for fischer-tropsch synthesis : Pure and encapsulated into alumina-containing matrices

Abstract Performance of the bulk hydrogenated ZrFe intermetallides both pure and encapsulated into alumina-containing matrix (Al 2 O 3 /Al, Al 2 O 3 ) was studied in catalysis of Fischer-Tropsch synthesis. Their structural, textural and surface properties were characterized by combination of such methods as XRD, SEM, TEM, nitrogen adsorption-desorption isotherms and XPS, and impact of these properties on catalytic activity and selectivity was analyzed. The highest activity per the surface Fe atom (~5·10 −19 CH x /at. Fe ·h) was obtained for pure active component, while the highest activity per the unit of volume (~168 g C 5 +/l · h) was revealed for a composite catalyst at 300°C, 3 MPa and space velocity ~7000 h −1 .