摘要:
The object of the present invention is to provide an oxygen storage material used for an exhaust gas purifying catalyst that is superior in stability at high temperatures. The composite oxide material of the invention comprises crystalline particles of a ceria-zirconia composite oxide with a pyrochlore structure and crystals of a lanthana-zirconia composite oxide with a pyrochlore structure existing on the particle surface, in which the crystals of the lanthana-zirconia composite oxide is solidly dissolved in at least a part of the surface of the crystalline particles of ceria-zirconia composite oxide. In the composite oxide material according to the present invention, the pyrochlore structure of the ceria-zirconia composite oxide is stabilized, and the decrease in oxygen storage capacity resulting from phase shift into the fluorite structure is suppressed.
摘要:
A method of synthesizing metal composite oxide, the method including: a step of separately introducing into a high-speed stirring apparatus a ceria composite oxide microparticle colloid having a mean particle diameter of 10 nm or less after adding a dispersant and an alumina microparticle colloid having a mean particle diameter of 10 nm or less after adding a dispersant; a step of synthesizing alumina-ceria composite oxide microparticles by allowing the ceria composite oxide microparticles and the alumina microparticles that have been introduced into the high-speed stirring apparatus to react in a microscopic space; and a step of applying a shearing force of 17000 sec−1 or more to the alumina-ceria composite oxide microparticles.
摘要:
An exhaust gas purification catalyst includes a composite oxide support, and a precious metal catalyst supported on the composite oxide support. The composite oxide support includes alumina, zirconia, ceria, a first additive element oxide and a second additive element oxide. The first additive element oxide contains an additive element selected from the group consisting of rare earth elements excluding cerium and alkali earth elements. The second additive element oxide contains an additive element selected from the group consisting of rare earth elements excluding cerium and alkali earth elements. In the composite oxide support, alumina is contained in a range of 30 to 40% by mass and zirconia is contained in a range of 36 to 46% by mass.
摘要:
A method of producing a porous composite metal oxide comprising the steps of: dispersing first metal oxide powder, which is an aggregate of primary particles each with a diameter of not larger than 50 nm, in a dispersion medium by use of microbeads each with a diameter of not larger than 150 μm, thus obtaining first metal oxide particles, which are 1 nm to 50 nm in average particle diameter, and not less than 80% by mass of which are not larger than 75 nm in diameter; dispersing and mixing up, in a dispersion medium, the first metal oxide particles and second metal oxide powder, which is an aggregate of primary particles each with a diameter of not larger than 50 nm, and which is not larger than 200 nm in average particle diameter, thus obtaining a homogeneously-dispersed solution in which the first metal oxide particles and second metal oxide particles are homogeneously dispersed; and drying the homogeneously-dispersed solution, thus obtaining a porous composite metal oxide.
摘要:
Disclosed is a water treatment system including a raw water tank, a module which includes a filtration membrane, a feed pump, a filtered water tank, a backwash pump which flows filtered water backward from the filtered water tank to the module, a valve and a channel which switch the direction of the water flow between the forward and reverse directions, a controller which suspends the supply of raw water from the raw water tank to the module, switches the valve and channel to the reverse direction, makes the backwash pump to supply filtered water from the filtered water tank to the module thereby backwashing the filtration membrane, and washing drainage treatment line including which treats backwashing drainage generated by backwashing of the filtration membrane, and returns the water to the raw water tank.
摘要:
[PROBLEMS] Disclosed is a heat shrinkable film having excellent heat resistance, content resistance, impact resistance, low/high temperature cycle resistance, and abrasion resistance. [MEANS FOR SOLVING PROBLEMS] Specifically disclosed is a heat shrinkable film comprising an intermediate layer (1), a front surface layer (2) and a back surface layer (3) so arranged as to sandwich the intermediate layer (1), and an overcoat layer (4) arranged on top of the front surface layer (2). The intermediate layer (1) contains first cyclic olefin resin and a random copolymer of ethylene and another α-olefin or a random copolymer of propylene and another α-olefin. The front surface layer (2) and the back surface layer (3) respectively contain second cyclic olefin resin and linear low-density polyethylene resin. Such a multilayer heat shrinkable film is formed into a tubular shape in such a manner that the overcoat layer (4) is on the outside. A secondary battery is fitted into the thus-formed tube of the multilayer heat shrinkable film and the tube is heat shrunk, so that there is obtained a wrapped battery.
摘要:
A composite oxide includes CeO2, ZrO2 and a metallic oxide being free from reacting with CeO2 and ZrO2 at 700° C. or more, preferably at 900° C. or more and further preferably at 1,000° C. or more. The composite oxide has a regulatory oriented phase, such as a pyrochlore phase, etc., in which at least a part of Ce cations and Zr cations are oriented regularly. The composite oxide makes a catalytic support. The CeO2—ZrO2 composite oxide and the reaction-free metallic oxide make barriers each other which suppress the granular growth when the composite oxide is subjected to high-temperature heat in a reducing heat treatment to form the regulatory oriented phase. The regulatory oriented phase improves the oxygen storage-and-release capability of the catalytic support. Thus, it is possible to simultaneously attain a large a specific surface area and a high oxygen storage-and-release capability.
摘要:
A method of making a ceramic shaped article from an inorganic raw material powder by extrusion molding is disclosed. The method comprises the steps of kneading an inorganic raw material powder with a plasticizer to obtain a kneaded body which is then molded by extrusion into a fluid having a high humidity to obtain a ceramic shaped article having no deformation and strain. The plasticizer is selected from the group consisting of mono-liquid type resin which is a water insoluble synthetic resin dissolved in a water soluble solvent and a hydraulic setting resin mainly consisting of polyurethane isocyanate prepolymer.
摘要:
The object of the present invention is to provide an exhaust gas purifying catalyst that can achieve high purification performance while suppressing H2S emissions. The object is solved by an exhaust gas purifying catalyst in which the top layer of a 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.
摘要:
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.