Advances in the development of novel cobalt Fischer-Tropsch catalysts for synthesis of long-chain hydrocarbons and clean fuels.

Catalytic removal of NO

Publisher Summary This chapter describes the essence of the catalytic chemistry of heteropoly compounds in solution and in the solid state. The catalytic properties of heteropoly compounds have drawn wide attention, owing to the versatility of these compounds as catalysts, which has been demonstrated both by successhl large-scale applications and by promising laboratory results. Heteropolyanions are polymeric oxoanions formed by condensation of more than two different mononuclear oxoanions. Heteropolyanions formed from one kind of polyanion are called isopolyanions. Acidic elements such as Mo, W, V, Nb and Ta, which are present as oxoanions in aqueous solution, tend to polymerize by dehydration at low pH, forming polyanions and water.Heteropoly catalysts can be applied in various ways. They are used as acid as well as oxidation catalysts. They are used in various phases, as homogeneous liquids, in two-phase liquids (in phase-transfer catalysis), and in liquid-solid and in gas-solid combinations, etc.

Catalytic Chemistry of Heteropoly Compounds

Heteropolyanions are polymeric oxoanions which are formed by the condensation of more than two different oxoanions [Eq. (1)l. Polyanions consisting of one kind of oxoanion are called isopolyanions [Eq. (2)]. Acidic elements such as Mo, W, V, Nb, and Ta are present as oxoanions in aqueous solutions and polymerize to form polyanions at low pH. Free acids (or acid forms) of these species are called heteropoly and isopoly acids, respectively. Here, the term “heteropoly compounds” is used for heteropoly acids and their salts.

Heterogeneous catalysis by heteropoly compounds of molybdenum and tungsten

Focuses on the surface chemistry and spectroscopy of chromium in inorganic oxides. Characterization of the molecular structures of chromium; Mechanics of hydrogenation-dehydrogenation reactions; Mobility and reactivity on oxidic surfaces.

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Surface Chemistry and Spectroscopy of Chromium in Inorganic Oxides.

Butadiene formation reaction from ethanol over various kinds of silica-magnesia having different MgO contents were studied from the standpoint of its acid-base catalysis. Maximum acidity was obtained at 50% MgO, while basicity increased with the MgO content. Silica-magnesia (85% MgO) having adequate acidity and basicity gave the maximum activity. The reaction mechanism and the roles of acidic and basic sites are discussed. The rate controlling step is the acetaldehyde formation catalyzed by basic sites.

Butadiene Formation from Ethanol over Silica-Magnesia Catalysts

12-Heteropolymolybdates as catalysts for vapor-phase oxidative dehydrogenation of isobutyric acid: 3. Molybdotungstophosphoric and molybdovanadophosphoric acids

Etsuro Echigoya

Papers

Butadiene Formation from Ethanol over Silica-Magnesia Catalysts

12-Heteropolymolybdates as catalysts for vapor-phase oxidative dehydrogenation of isobutyric acid: 3. Molybdotungstophosphoric and molybdovanadophosphoric acids

Kinetic and adsorption studies on vapor-phase catalytic oxidation of olefins over silver

12-Heteropolymolybdates as catalysts for vapor-phase oxidative dehydrogenation of isobutyric acid: 2. Group Ib, IIb, IIIb, and VIII metal salts

12-heteropolymolybdates as catalysts for vapor-phase oxidative dehydrogenation of isobutyric acid: I. Alkali and alkaline-earth metal salts