Abstract: There are provided (i) a heat resistant catalyst sheet having an aramid fiber and a catalyst component-containing titania fiber; and (ii) a process for producing a heat resistant catalyst sheet, which has the step of making paper from a mixture of an aramid fiber and a catalyst component-containing titania fiber.

Abstract: A titanium hydroxide is provided which can be utilized for producing a photocatalyst exhibiting a superior photocatalytic activity by irradiation of visible light. The titanium hydroxide has a primary differential spectrum (of radial structure function in connection with titanium K absorption edge) having maximal intensities (U1 and U2) and minimal intensities (L1 and L2) at interatomic distances in the range of from 1.4 Å to 2.8 Å, the maximal intensities being at an interatomic distance of from 1.4 Å to 1.7 Å and of from 2.2 Å to 2.5 Å and the minimal intensities being at an interatomic distance of from 1.9 Å to 2.2 Å and of from 2.5 Å to 2.8 Å; and index X calculated by the equation X=(U2−L2)/(U1−L1) of about 0.06 or more.

Abstract: The present invention provides a porous titania, which has an anatase-form crystalline structure, an anatase-form crystallite diameter of 3 nm to 10 nm, a degree of anatase crystallinity of 60% or more, a BET specific surface area of 10 m2/g or more, a total pore volume of 0.05 cm3/g or more, and a volume for pores having a pore radius of 1 nm or more of 0.02 cm3/g or more, and the porous titania and the catalyst comprising the porous titania of the present invention exhibit an excellent catalytic activity for removal of nitrogen oxides, oxidation of organic substances, decomposition of dioxine compounds, as well as decomposition and removal of organic solvents, agricultural chemical and surfactant.

Abstract: A continuous fiber of titania are made having an average diameter per a monofilament of from 5 to 50 &mgr;m, which has a BET specific surface area of 10 m2/g or more, a pore volume of 0.05 cc/g or more, a volume of pores having a pore diameter of not less than 10 angstroms being 0.02 cc/g or more and an average tensile strength per a monofilament of 0.1 GPa or more, or which has an average tensile strength per a monofilament of 0.5 GPa or more.

Abstract: The present invention provides a porous titania, which has an anatase-form crystalline structure, an anatase-form crystallite diameter of 3 nm to 10 nm, a degree of anatase crystallinity of 60% or more, a BET specific surface area of 10 m2/g or more, a total pore volume of 0.05 cm3/g or more, and a volume for pores having a pore radius of 1 nm or more of 0.02 cm3/g or more, and the porous titania and the catalyst comprising the porous titania of the present invention exhibit an excellent catalytic activity for removal of nitrogen oxides, oxidation of organic substances, decomposition of dioxine compounds, as well as decomposition and removal of organic solvents, agricultural chemical and surfactant.

Abstract: The present invention provides a porous titania , which has an anatase-form crystalline structure, an anatase-form crystallite diameter of 3 nm to 10 nm, a degree of anatase crystallinity of 60% or more, a BET specific surface area of 10 m2/g or more, a total pore volume of 0.05 cm3/g or more, and a volume for pores having a pore radius of 1 nm or more of 0.02 cm3/g or more, and the porous titania and the catalyst comprising the porous titania of the present invention exhibit an excellent catalytic activity for removal of nitrogen oxides, oxidation of organic substances, decomposition of dioxine compounds, as well as decomposition and removal of organic solvents, agricultural chemical and surfactant.

Abstract: A catalyst filter comprising titania catalyst fiber and at least one layer of nonwoven fabric of polymer fiber, which can remove dust and nitrogen oxides from exhaust gas at the same time, has a high catalytic activity and maintains the high catalytic activity even after vibrating the filter to shake off calcium hydroxide and dust.

Abstract: A titanium oxide showing sufficiently high photocatalytic activities by irradiation of visible light is provided. Using the titanium oxide, an excellent photocatalyst and photocatalyst coating composition are also provided. The titanium oxide has a selected ion chromatogram in which an evolution gas having 28 of a ratio of mass number to electric charge quantity exhibits at least one peak at about 600° C. or higher, the selected ion chromatogram being measured in a thermogravimetry-mass-spectroscopy.

Abstract: A process for producing a titanium oxide is provided which comprises (i) a step of calcining a titanium compound in the presence of ammonia gas or (ii) steps of treating a titanium compound with heat in the presence of ammonia gas and calcining the heat-treated titanium compound. The titanium oxide obtained in the present invention exhibits a sufficiently high photocatalytic activity by irradiation of visible light.

Abstract: There is provided a titanium hydroxide having a nitrogen content of 2.3% by weight or more in terms of nitrogen atom based on the titanium hydroxide and/or having a nitrogen content of about 3.3% by weight or more in terms of nitrogen atom based on the titanium oxide obtained after calcining the titanium hydroxide in air at about 400° C. The titanium hydroxide may be utilized as a raw material for producing a photocatalyst which exhibits a superior photocatalytic activity by irradiation of visible light.

Abstract: A metal oxide powder except &agr;-alumina, is disclosed comprising polyhedral particles having at least 6 planes each, a number average particle size of from 0.1 to 300 &mgr;m, and a D90/D10 ratio of 10 or less where D10 and D90 are particle sizes at 10% and 90% accumulation, respectively from the smallest particle size side in a cumulative particle size curve of the particles. This metal oxide powder contains less agglomerated particles, and has a narrow particle size distribution and a uniform particle shape.

Abstract: A continuous fiber of titania are made having an average diameter per a monofilament of from 5 to 50 &mgr;m, which has a BET specific surface area of 10 m2/g or more, a pore volume of 0.05 cc/g or more, a volume of pores having a pore diameter of not less than 10 angstroms being 0.02 cc/g or more and an average tensile strength per a monofilament of 0.1 GPa or more, or which has an average tensile strength per a monofilament of 0.5 GPa or more.

Abstract: A method for producing a catalyst component-carrying titania fibers is provided, which has large specific surface area, large pore volume and a high catalyst activity. The method comprises steps of adding a catalyst component to the solution of a titanium alkoxide or to the hydrosis/polymerizatin reaction mixture and/or to the spinning solution, and treating a precursor fiber with water vapor before and/or during calcination.

Abstract: A continuous fiber of titania are made having an average diameter per a monofilament of from 5 to 50 .mu.m, which has a BET specific surface area of 10 m.sup.2 /g or more, a pore volume of 0.05 cc/g or more, a volume of pores having a pore diameter of not less than 10 angstroms being 0.02 cc/g or more and an average tensile strength per a monofilament of 0.1 GPa or more, or which has an average tensile strength per a monofilament of 0.5 GPa or more.

Abstract: A complex metal oxide powder having at least two metal elements, which contains polyhedral particles each having at least 6 planes, a number average particle size of from 0.1 to 500 .mu.m, and a D.sub.90 /D.sub.10 ratio of 10 or less in which D.sub.10 and D.sub.90 are particle sizes at 10% and 90% accumulation, respectively from the smallest particle size side in a cumulative particle size curve of the particles, and an yttrium-aluminum garnet powder containing polyhedral particles each having at least 6 planes, and a number average particle size of 20 to 500 .mu.m. These complex metal oxides contain less agglomerated particles, and have a narrow particle size distribution and a uniform particle shape.