摘要:
The present invention relates to a composite oxide comprising ceria, praseodymia and alumina, wherein the cerium : praseodymium molar ratio of the composite oxide is 84:16 or less, as well as to a method of preparing the composite oxide and to its use, in particular in a method of treating an exhaust gas stream.
摘要:
Multi-metal oxide mass containing MO, Bi and Fe with general stoichiometry I, Mo 12 Bi a Co b Fe c K d Si e O x (I), with a = 0.5 to 1, b = 7 to 8.5, c = 1.5 to 3.0, d = 0 to 0.15, e = 0 to 2.5 and x = stoichiometric coefficient of O 2- to guarantee electrical neutrality of the multi-metal oxide, as well as 12 - b - 1.5 ⋅ c = A and 0.5 ≤ A ≤ 1.5, 0.2 ≤ a/A ≤ 1.3 and 2.5 ≤ b/c ≤ 9 and the use thereof.
摘要:
The present invention relates to a process for the preparation of nanoparticulate zinc oxide in the form of aqueous suspensions or in the form of pulverulent solid. Furthermore, the invention relates to the use of zinc oxide particles and suspensions prepared in this way in cosmetic sunscreen preparations, as stabilizer in plastics, in paints, in coatings and as antimicrobial active ingredient.
摘要:
The present invention relates to a method for producing surface-modified nanoparticulate particles of at least one metal oxide, metal hydroxide, and/or metal oxide hydroxide, and aqueous suspensions of said particles. The invention further relates to the surface-modified nanoparticulate particles of at least one metal oxide, metal hydroxide, and/or metal oxide hydroxide and aqueous suspensions of said particles obtainable with said method, and the use thereof in cosmetic sun protection preparations, as stabilizers in plastics, and as antimicrobial agents.
摘要:
A shaped catalyst body for producing ethylene oxide by gas-phase oxidation of ethylene, comprising silver deposited on a porous refractory support, the shaped catalyst body having a first face side surface, a second face side surface and a circumferential surface, characterized by a content of at least 20 wt.-% of silver, relative to the total weight of the shaped catalyst body; a cylinder structure with a plurality of void spaces running in the cylinder periphery along the cylinder height to form a multilobe structure; a plurality of passageways extending from the first face side surface to the second face side surface, outer passageways being arranged around a central passageway with one outer passageway being assigned to each lobe, wherein neighboring outer passageways are arranged essentially equidistantly to each other and the outer passageways are arranged essentially equidistantly to the central passageway; a shortest distance A between two neighboring passageways in the range of 0.6 to 1.3 mm; a shortest distance B between each outer passageway and the circumferential surface in the range of 1.1 to 1.8 mm; and a BET surface area in the range of 1.6 to 3.0 m 2 /g. The shaped catalyst bodies allow for a favorable balance between mechanical stability, pressure drop and selectivity. The invention also relates to a process for producing ethylene oxide by gas-phase oxidation of ethylene, comprising reacting ethylene and oxygen in the presence of a shaped catalyst body as defined above. The invention further relates to a process for preparing a shaped catalyst body as above, comprising i) impregnating a refractory support having a BET surface area in the range of 1.4 to 2.5 m 2 /g with a silver impregnation solution; and ii) subjecting the impregnated refractory support to a calcination process; wherein steps i) and ii) are optionally repeated.