The film is formed using one of two film-forming materials. The first film-forming material contains: particles containing a crystal phase of a rare earth element fluoride; particles containing a crystal phase of a rare earth element oxide; and particles containing a crystal phase of a rare earth element ammonium fluoride double salt. The second film-forming material contains: particles containing a crystal phase of a rare earth element fluoride; and particles containing a crystal phase of a rare earth element oxide and a crystal phase of a rare earth element ammonium fluoride double salt. If a spray coated film is to be formed by means of thermal spraying using this film-forming material or film-forming slurry in particular, it is possible to form a rare earth element oxyfluoride spray coated film without the need for excessive heat.

The object of the present invention is to provide a high-performance exhaust gas purifying catalyst that can achieve oxygen absorption/release capacity and NOx purification performance. The object is solved by an exhaust gas purifying catalyst, which comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure in the upstream part of the catalyst coating layer, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % of the total cation amount, and has a molar ratio of (cerium+the additional element):(zirconium) of 43:57 to 48:52.

The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H.sub.2S emissions. The object is solved by an exhaust gas purifying catalyst in which the lower layer of the catalyst coating layer comprises a ceria-zirconia composite oxide having a pyrochlore-type ordered array structure, in which the ceria-zirconia composite oxide contains at least one additional element selected from the group consisting of praseodymium, lanthanum, and yttrium at 0.5 to 5.0 mol % in relation to the total cation amount, and the molar ratio of (cerium+additional element):(zirconium) is within the range from 43:57 to 48:52.

A process for preparing a mesoporous material, e.g., transition metal oxide, sulfide, selenide or telluride, Lanthanide metal oxide, sulfide, selenide or telluride, a post-transition metal oxide, sulfide, selenide or telluride, and metalloid oxide, sulfide, selenide or telluride. The process comprises providing a micellar solution comprising a metal precursor, an interface modifier, a hydrotropic or lyotropic ion precursor, and a surfactant; and heating the micellar solution at a temperature and for a period of time sufficient to form the mesoporous material. A mesoporous material prepared by the above process. A method of controlling nano-sized wall crystallinity and mesoporosity in mesoporous materials. The method comprises providing a micellar solution comprising a metal precursor, an interface modifier, a hydrotropic or lyotropic ion precursor, and a surfactant; and heating the micellar solution at a temperature and for a period of time sufficient to control nano-sized wall crystallinity and mesoporosity in the mesoporous materials. Mesoporous materials and a method of tuning structural properties of mesoporous materials.

Various embodiments relate to separation of terbium(III,IV) oxide. In various embodiments, present invention provides a method of separating terbium(III,IV) oxide from a composition. The method can include contacting a composition including terbium(III,IV) oxide and one or more other trivalent rare earth oxides with a liquid including acetic acid to form a mixture. The contacting can be effective to dissolve at least some of the one or more other trivalent rare earth oxides into the liquid. The method can include separating undissolved terbium(III,IV) oxide from the mixture, to provide separated terbium(III,IV) oxide.

A ceria-zirconia-based composite oxide which has a crystal phase of the composite oxide of a single solid-solution phase even after exposure to a high temperature over a long time and has a small change in mode pore diameter and in pore volume before and after a high temperature durability test is provided. This is realized by a ceria-zirconia-based composite oxide having a chemical composition, by mass ratio, of zirconia: 30% to 80%, a total of oxides of one or more elements selected from yttrium and rare earth elements having atomic number 57 to 71 (except cerium and promethium): 0% to 20%, and a balance of ceria and unavoidable impurities, in which ceria-zirconia-based composite oxide, the composite oxide is deemed to be a single solid-solution phase in an X-ray diffraction pattern after a durability test which heats the oxide in the atmosphere at a temperature condition of 1100 C. for 5 hours and has a ratio (b/a) of mode pore diameter (b) of a pore distribution after a durability test which heats the oxide in the atmosphere at a temperature condition of 1100 C. for 5 hours to the mode pore diameter (a) before the durability test of 1.0b/a2.0 and/or has a ratio (d/c) of pore volume (d) after a durability test which heats the oxide in the atmosphere at a temperature condition of 1100 C. for 5 hours to the pore volume (c) before the durability test of 0.20d/c1.00.

A purifying method of removing yttrium from a yttrium-containing europium oxide, including the steps of (A) dissolving a yttrium-containing europium oxide in a solvent to produce a saturated yttrium-containing europium compound solution; (B) performing a low-temperature recrystallization treatment on the saturated yttrium-containing europium compound solution to produce a europium-containing precipitate; (C) calcining the europium-containing precipitate, followed by dissolving the calcined europium-containing precipitate in an inorganic acid to produce a europium-containing metal functioning as an electrolyte; and (D) performing an electrochemical reduction process on the electrolyte which the europium-containing metal functions as, followed by introducing a precipitant thereto to produce a europium compound. The method removes yttrium from yttrium-containing europium oxide present in phosphor powder to purify europium oxide, thereby recycling, purifying and reusing europium valuable metal to reduce environmental pollution.

A method for obtaining rare earth element compositions may include providing a dispersed aqueous suspension of a particulate material including at least one rare earth element compound and kaolinite. The method may further include adding to the suspension a selective flocculation polymer that facilitates separation of at least a portion of the at least one rare earth element compound from the kaolinite by flocculating the kaolinite and allowing particles of the rare earth element compound to be or remain deflocculated. The method may also include allowing the suspension containing the polymer to separate in a selective flocculation separator into layers including a flocculated product layer and a deflocculated layer containing the portion of the at least one rare earth element compound. The method may further include extracting each of the separated layers from the separator. The rare earth element compound may include La.sub.2O.sub.3, CeO.sub.2, Nd.sub.2O.sub.3, or Y.sub.2O.sub.3.

An anticorrosive pigment comprising an aluminum polyphosphate comprises at least one cerium-based compound and/or one lanthanum-based compound and/or one praseodymium-based compound. An anticorrosive paint incorporating the pigment is also provided.

Nanowires useful as heterogeneous catalysts are provided. The nanowire catalysts are useful in a variety of catalytic reactions, for example, the oxidative coupling of methane to ethylene. Related methods for use and manufacture of the same are also disclosed.