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Mixed oxide
About: Mixed oxide is a research topic. Over the lifetime, 5224 publications have been published within this topic receiving 115567 citations.
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TL;DR: In this paper, cobalt and lead based mixed oxide catalysts were tested for their soot oxidation ability in addition to a mixed oxide formerly marketed as ceramic paint, a home made set was also prepared by incipient wetness impregnation of a cobalt oxide powder with a lead acetate solution and subsequent calcination.
Abstract: In this study, cobalt and lead based mixed oxide catalysts were tested for their soot oxidation ability In addition to a mixed oxide formerly marketed as ceramic paint, a home made set was also prepared by incipient wetness impregnation of a cobalt oxide powder with a lead acetate solution and subsequent calcination The materials investigated in this study were shown to decrease the peak combustion temperature of home made soot from 500 to 385 °C in air Soot oxidation tests under inert (N2) atmospheres revealed that the oxidation took place by using the lattice oxygen of the catalyst Reaction temperature could be further decreased when these mixed oxide catalysts were impregnated with platinum An optimum platinum loading was determined as 05 wt% based on the peak combustion temperature of the soot The role of Pt was to assist the oxygen transfer from the gas phase to the lattice It was observed that NO2 is a better oxidizing agent as compared to air whereas NO had hardly any activity against soot oxidation reaction When the mixed oxide catalyst was impregnated with platinum, the peak combustion temperature was measured as 310 °C in the presence of NOx and air The catalyst's unique performance was in terms of the rate of soot oxidation Under the experimental conditions studied here, the soot oxidation was so facile that the oxygen in the gas phase was completely depleted This stream of oxygen depleted and CO enriched gas phase can be used to reduce NOx in the presence of a downstream or a co-catalyst
54 citations
TL;DR: In this paper, a significant change in sintering behavior has been detected going from a titania rich to a strontia rich composition, and the influence of zirconia abrasion from milling balls has been identified to be equal to the titania excess of the same amount.
Abstract: In order to control the preparation of strontium titanate with a well-defined Sr/Ti stoichiometry produced by the mixed oxide route, dilatometric experiments have been conducted for compositions with Sr/Ti ratios ranging from 0.996 to 1.005. A significant change in sintering behavior has been detected going from a titania rich to a strontia rich composition. Combining observations of the microstructural evolution during different stages of sintering with results on defect chemistry from the literature makes an assessment of the basic mechanisms of sintering possible. The influence of zirconia abrasion from milling balls has been identified to be equal to a titania excess of the same amount. By means of dilatometric measurements it is possible to evaluate the A/B ratio with accuracy higher than 0.2 mol% from the shrinkage curves, providing a highly sensitive tool for the analysis of the stoichiometry in SrTiO 3 .
54 citations
TL;DR: In this article, a spray pyrolysis method was used to synthesize a CdO-MnO2 mixed oxide film, which is shown to be highly sensitive to ethanol at ambient temperature and to formaldehyde vapour at 393 K.
Abstract: CdO–MnO2 mixed oxide films are synthesized using a spray pyrolysis method. The structural study confirms the polycrystalline nature of the film and also confirms that the films are in a mixed oxide state. The morphological study reveals that the crystallite size is around 30 nm to 40 nm in size with spherical morphology. Energy dispersive spectroscopy confirms the presence of cadmium, manganese and oxygen in a mixed oxide state. The prepared CdO–MnO2 film is highly sensitive to ethanol vapours at ambient temperature. The resistance of the film decreases drastically when it is exposed to ethanol and formaldehyde vapours. The prepared CdO–MnO2 is highly sensitive to ethanol at ambient temperature and to formaldehyde vapour at 393 K. The sensitivity, selectivity, response time, recovery time and stability of the CdO–MnO2 film towards ethanol and formaldehyde sensing are reported in the present work.
54 citations
Patent•
30 Nov 1995TL;DR: In this article, the authors present a solution of aqueous solution of soluble compounds of cerium and zirconium (and optionally yttrium) for the treatment of vehicular exhaust gases.
Abstract: Cerium/zirconium mixed oxides (optionally including yttrium values), comprising solid solutions thereof, having contents of zirconium of up to 60 atom % and having thermally stable, very high specific surface areas at least greater than 80 m 2 /g, preferably at least 100 m 2 /g and more preferably at least 150 m 2 /g, are well suited as catalysts and/or catalyst supports, notably for the treatment/conversion of vehicular exhaust gases; such Ce x Zr 1-x O 2 particulates are conveniently prepared by thermally treating an aqueous solution of soluble compounds of cerium and zirconium (and optionally yttrium), e.g. the nitrates thereof, present in the desired stoichiometric amounts, and thence recovering and, if appropriate, calcining the reaction product thus formed.
54 citations
TL;DR: In this article, a porous oxide semiconductor material made of a titanium-niobium oxide was evaluated as a heterogeneous photocatalyst for the photolysis of organic compounds in water.
54 citations