Abstract: Provided is a composite oxide which is suitable as a co-catalyst for an exhaust gas purifying catalyst or the like, has high heat resistance, and has an excellent oxygen absorbing and desorbing capability at low temperatures. The composite oxide contains Ce and Zr, wherein the Ce content is 30 to 80 at % and the Zr content is 20 to 70 at %, based on the total of Ce and Zr being 100 at %, or further contains particular element M, wherein the Ce content is not less than 30 at % and less than 80 at %, the Zr content is not less than 20 at % and less than 70 at %, and the content of element M is more than 0 at % and not more than 15 at %, based on the total of Ce, Zr, and element M being 100 at %; wherein the composite oxide has CaF2-type or CaF2-like structure phase, wherein the ratio of an actual lattice parameter in the (311) plane to the theoretical is 1.000, and wherein the composite oxide has a property of exhibiting a total pore volume of not less than 0.30 cc/g after calcination at 1000° C.

Abstract: Provided is solid electrolyte utilizing a composite oxide of a RP-type structure, that is useful for achieving strong electromotive force and enhanced current-voltage characteristics of a fuel battery, has enhanced ion conductivity and sufficiently inhibited electronic conductivity, and is capable of intercalation of a large amount of water or hydrogen groups, as well as a solid electrolyte membrane, a fuel battery cell, and a fuel battery. The solid electrolyte and the solid electrolyte membrane of the present invention has been obtained by subjecting a particular composite oxide of a RP-type structure or a membrane thereof to a treatment of at least one of hydroxylation and hydration, and has a property that the mass determined by TG measurement at 400° C. is less than that at 250° C. by not less than 4.0%.

Abstract: A catalyst, a hydrocarbon steam reforming catalyst, and a method for producing the same are provided. A catalytic metal containing at least Ni is supported on a composite oxide containing R, Zr, and oxygen, at a composition of not less than 10 mol % and not more than 90 mol % of R, not less than 10 mol % and not more than 90 mol % of Zr, and not less than 0 mol % and not more than 20 mol % of M (M: elements other than oxygen, R, and Zr), with respect to the total of the elements other than oxygen being 100 mol %, wherein the composite oxide has a specific surface area of 11 to 90 m2/g, and the largest peak in the wavelength range of 200 to 800 cm?1 of Raman spectrum with a full width at half maximum of 20 to 72 cm?1.

Abstract: A composite oxide is provided which has large oxygen absorption and desorption over a wide temperature range, in particular in a higher temperature range of not lower than 700° C. and/or in a lower temperature range of not higher than 400° C. The composite oxide contains oxygen, R composed of at least one of Ce and Pr, and Zr at a particular ratio, and optionally a particular ratio of M composed of at least one element selected from alkaline earth metals and the like.

Abstract: Provided are a solid electrolyte membrane useful in achieving strong electromotive force in a fuel battery, and a fuel battery cell produced with this membrane. The solid electrolyte membrane includes a substrate made of a sheet material and having a plurality of openings penetrating the substrate in its thickness direction, and a solid electrolyte layer provided on at least one of the faces of the substrate. The fuel battery cell includes a solid electrolyte membrane having the solid electrolyte layer on one of the faces of the substrate, and a catalyst layer containing a precious metal and provided on the other of the faces of the substrate, with the solid electrolyte layer and the catalyst layer being in contact with each other in the openings of the substrate.

Abstract: There is provided an all-solid lithium battery having excellent output characteristics. The battery has a cathode, an electrolyte layer, and an anode. The cathode contains a cathode active material represented by formula (1) and a sulfide solid electrolyte, and the electrolyte layer contains a sulfide solid electrolyte: LiaNibCocMndMeOf+???(1) (1.01?a?1.05; f: 2 or 4; ?: not less than ?0.2 and not more than 0.2; M: Mg, Ca, Y, rare earth elements, etc.; provided that when f=2, 0?b?1, 0?c?1, 0?d?1, 0?e?0.5, and b+c+d+e=1; when f=4, 0?b?2, 0?c?2, 0?d?2, 0?e?1, and b+c+d+e=2).

Abstract: A composite oxide is provided which has large oxygen absorption and desorption over a wide temperature range, in particular in a higher temperature range of not lower than 700° C. and/or in a lower temperature range of not higher than 400° C. The composite oxide contains oxygen, R composed of at least one of Ce and Pr, and Zr at a particular ratio, and optionally a particular ratio of M composed of at least one element selected from alkaline earth metals and the like.

Abstract: A composite oxide having oxygen absorbing and desorbing capability containing 90 to 100 weight % total of cerium, zirconium, and hafnium based on a total amount of metals contained in the composite oxide, the total amount of cerium, zirconium, and hafnium consisting of 14.0 to 70.5 at % cerium, 29.49 to 72.5 at % zirconium, and 0.01 to 13.5 at % hafnium, wherein degree of solid solution of the composite oxide is not lower than 70%, and wherein the composite oxide has reducing property that not less than 90% of tetravalent cerium contained in the composite oxide is reduced into trivalent cerium when the composite oxide is held at 600.degree. C. under a reducing atmosphere; and a method for preparing the composite oxide including the steps of preparing a composite salt from a starting material solution wherein 85 weight % or more of the cerium ions are Ce.sub.4+ by coprecipitation, and subjecting the resulting precipitate to a particular calcining steps including reducing calcination.

Abstract: A method for preparing a composite oxide having oxygen absorbing and desorbing capability involves the steps of: providing a starting composite oxide comprising cerium oxide, zirconium oxide, and hafnium oxide; subjecting the starting composite oxide to heating-deoxidation to give a deoxidized composite oxide; and subjecting the deoxidized composite oxide to heating-oxidation.

Abstract: A composite oxide having oxygen absorbing and desorbing capability contains 4.99-98.89% by weight of cerium oxide, 1-95% by weight of zirconium oxide, 0.01-20% by weight of hafnium oxide, and 0.1-10% by weight of an additional metal oxide selected from titanium oxide, tungsten oxide, nickel oxide, copper oxide, iron oxide, aluminum oxide, silicon oxide, beryllium oxide, magnesium oxide, calcium oxide, strontium oxide, barium oxide, oxides of rare earth metals other than cerium, and mixtures thereof. The composite oxide includes .PHI. phase as a crystal phase, and has oxygen absorbing and desorbing capability of at least 100 .mu.mol/g at 400.degree.-700.degree. C. The composite oxide is prepared by the wet method or by the dry method.

Abstract: A composite oxide having oxygen absorbing and desorbing capability contains 4.99-98.99% by weight of cerium oxide, 1-95% by weight of zirconium oxide and 0.01-20% by weight of hafnium oxide. The composite oxide includes .PHI.' phase as a crystal phase and has oxygen absorbing and desorbing capability of at least 100 .mu.mol/g at 400.degree. to 700.degree. C.

Abstract: A compound oxide having oxygen absorbing and desorbing capability contains 4.99-98.99% by weight of cerium oxide, 1-95% by weight of zirconium oxide and 0.01-20% by weight of hafnium oxide. The compound oxide has an oxygen absorbing and desorbing capability of at least 100 .mu.mol/g at 400-700.degree. C. and a specific surface area of at least 10 m.sup.2 /g after heating at 900.degree. C. for 5 hours.