Abstract: A process to produce mixed metal oxides and metal oxide compounds. The process includes evaporating a feed solution that contains at least two metal salts to form an intermediate. The evaporation is conducted at a temperature above the boiling point of the feed solution but below the temperature where there is significant crystal growth or below the calcination temperature of the intermediate. The intermediate is calcined, optionally in the presence of an oxidizing agent, to form the desired oxides. The calcined material can be milled and dispersed to yield individual particles of controllable size and narrow size distribution.
Type:
Grant
Filed:
September 5, 2001
Date of Patent:
December 13, 2005
Assignee:
Altair Nanomaterials Inc.
Inventors:
Bruce J. Sabacky, Timothy M. Spitler, Jan Prochazka
Abstract: This composite oxide powder can secure a large pore volume even after calcination at high temperature and, when a catalyst is formed by loading a noble metal on this composite oxide powder, noble metal grain growth can be suppressed. The composite oxide powder comprises particles of an oxide of a metal M1 and an oxide of a metal M2 which does not dissolve in the oxide of the metal M1, the oxide of the metal M1 and the oxide of the metal M2 being dispersed at the nanometer level. Since different oxides serve as a barrier to each other, sintering is suppressed. Therefore, in the case of composite oxide powder comprising Ce as a metal M1 and Al as a metal M2, grain growth is small even after exposed to high temperature and pores of 3.5-100 nm secure a volume of 0.07 cc/g or more after calcination at 600° C. for 5 hours and a volume of 0.04 cc/g or more after calcination at 800° C. for 5 hours.
Abstract: A positive active material for non-aqueous electrolyte secondary battery is provided comprising lithium manganese oxide having such a spinel structure that the half-width (2?) of the reflection peak corresponding to 440 plane as determined by X-ray diffractometry using CuK? ray is not greater than 0.145°. The use of this positive active material makes it possible to obtain a secondary battery which exhibits a good cycle life performance at room temperature and high temperatures and a reduced capacity drop when stored at high temperatures.
Abstract: The invention is directed to open-framework and microporous solids well suited for use in catalysis and ion exchange. The microporous solids are constructed by using a salt template which can be readily removed without destroying the framework of the micropore. Various microporous solids can be formed having different geometric structures depending upon the templating salt used and the concentration. Examples of two compounds include Na2Cs[Mn3(P2O7)2]Cl and K2.02Cs2.90[Cu3(P2O7)2]Cl2.92. Both compounds have 3-D (Mn, Cu)—P—O frameworks.
Abstract: The present invention relates to an oxide sintered body having a perovskite structure represented with a chemical formula of MRuO3 (M: one or more types among Ca, Sr, Ba), characterized in that the total content of alkali metals such as Na, K, and Fe, Ni, Co, Cr, Cu, Al is 100 ppm or less, the content of respective elements U, Th is 10 ppb or less, and the relative density is 90% or more, and provides an oxide sintered body and the manufacturing method thereof having a pervoskite structure represented with the chemical formula MRuO3 (M: one or more types among Ca, Sr, Ba) by using a MRuO3 sintered body raw material refined to a high density of 4N or more, which enables sintering at low temperatures, and which is capable of obtaining a high-density sintered body.
Abstract: The present invention relates to a single step process for the synthesis of nanoparticles of phase pure ceramic oxides of a single or a multi-component system comprising one or more metal ions. The process comprises preparing a solution containing all the required metal ions in stoichiometric ratio by dissolving their respective soluble salts in an organic solvent or in water, preparing a precursor, adjusting the nitrate/ammonia content in the system, and heating the system.
Type:
Grant
Filed:
February 28, 2002
Date of Patent:
December 28, 2004
Assignee:
Council of Scientific and Industrial Research
Inventors:
Jose James, Rajan Jose, Asha Mary John, Jacob Koshy
Abstract: A perovskite feedstock (powder or preform) is placed in a high-pressure cell of a high pressure/high temperature (HP/HT) apparatus and subjected to pressures in excess of about 2 kbar and temperatures above about 800° C. for a time adequate to increase the density of the preform.
Abstract: Metal oxides having a perovskite or perovskite-like crystal structure are prepared by a process comprising subjecting a mixture of starring powders to a high energy milling sufficient to induce chemical reaction of the components and thereby directly mechanosynthesize said metal oxide in the form of a perovskite or a perovskite-like material having a nanocrystalline structure as determined by X-ray diffractometry. The process according to the present invention is simple, efficient, not expensive and does not require any heating step for producing a perovskite that may easily show a very high specific surface area. Another advantage is that the perovskite obtained according to the present invention also has a high density of lattice defects thereby showing a higher catalytic activity, a characteristic which is highly desirable in their eventual application as catalysts and electronic conductors.
Abstract: The invention is directed to open-framework and microporous solids well suited for use in catalysis and ion exchange. The microporous solids are constructed by using a salt template which can be readily removed without destroying the framework of the micropore. Various microporous solids can be formed having different geometric structures depending upon the templating salt used and the concentration. Examples of two compounds include Na2Cs[Mn3(P2O7)2]Cl and K2.02Cs2.90[Cu3(P2O7)2]Cl2.92. Both compounds have 3-D (Mn,Cu)—P—O frameworks.
Abstract: This invention relates to a process for the production of an oxide of a metal A by heating precursors of the oxide of a metal A, in the presence of an oxygen partial pressure control agent comprising an oxide of a metal B that is capable of assuming multiple valence numbers. The process is carried out under a condition that an ionization tendency relationship of Ai+<Bj+<A0 is satisfied, where i is a valence number of the metal A in the oxide to be produced and j is a valence number of the metal B in the oxygen partial pressure control agent.
Type:
Grant
Filed:
December 12, 2000
Date of Patent:
March 2, 2004
Assignee:
Agency of Industrial Science & Technology, Ministry of
International Trade & Industry
Inventors:
Naoki Shirakawa, Shin-Ichi Ikeda, Hiroshi Bando
Abstract: A method for producing a barium-containing composite metal oxide, comprising calcining a mixture of a barium compound and a metal compound comprising at least one metal selected from the group consisting of magnesium, aluminum, europium, manganese, strontium, calcium, terbium, zinc and titanium, or calcining a barium-containing composite metal salt comprising barium and at least one metal selected from the group consisting of magnesium, aluminum, europium, manganese, strontium, calcium, terbium, zinc and titanium, in a gas comprising a hydrogen halide and water vapor.
Abstract: The present invention relates to high oxygen ion conducting/oxygen storage (OIC/OS) materials, a catalyst employing the OIC/OS materials, and a method for converting hydrocarbons, carbon monoxide and nitrogen oxides using the catalyst. The OIC/OS materials have significantly higher oxygen storage capacity than that predicted based on Ce content due to the unexpected high and facile redox activity of the added niobium. These materials are further characterized by having a tetragonal crystalline structure under oxidizing conditions (in air) up to about 1,200° C. and a cubic crystalline structure in reducing conditions (5% hydrogen) up to about 1,000° C. for 24 hours. These materials comprise, based upon 100 mole % of the metal component in the material, up to about 95 mole % zirconium, up to about 50 mole % cerium, about 0.5 to about 15 mole % rare earth metal(s), alkaline earth metal(s) or a combination thereof, and about 0.5 to about 15 mole % niobium.
Abstract: Disclosed is a positive electrode active material for a lithium ion secondary battery, including lithium-transition metal composite oxide of a layer crystal structure, in which the lithium-transition metal composite oxide contains an element that improves conductivity of electrons in the lithium-transition metal composite oxide. Use of this positive electrode active material can improve cycle characteristics, high rate characteristics and thermal stability of lithium ion secondary batteries. Furthermore, by use of this positive electrode active material, gas generation in batteries can be decreased.