摘要:
A complex fluoride A 2 MF 6 wherein M is a tetravalent element Si, Ti, Zr, Hf, Ge or Sn, A is an alkali metal Li, Na, K, Rb or Cs is prepared by providing a first solution containing a fluoride of M, providing a second solution containing a compound of A and/or the compound of A in solid form, mixing the first solution with the second solution and/or the solid for reacting the fluoride of M with the compound of A, and recovering the resulting solid product via solid-liquid separation.
摘要:
The invention relates to a composition comprising cerium and zirconium oxides, containing at least 30 wt.-% cerium oxide. Following calcination at a temperature of 900°C for 4 hours, the composition has two populations of pores, the diameters of the first population being centered around a value of between 5 nm and 15 nm for a composition containing 30% to 65% cerium oxide or between 10 nm and 20 nm for more than 65% cerium oxide and the diameter of the second population being centered around a value of between 45 nm and 65 nm for 30% to 65% cerium oxide or between 60 nm and 100 nm for more than 65% cerium oxide.
摘要:
A process is disclosed for the preparation of lithium zirconate and doped lithium zirconates for use as regenerable carbon dioxide sorbants by wet mixing zirconium hydroxide with lithium carbonate and then calcining the mixture. Due to the improved physical properties resulting from the disclosed preparation process, the lithium zirconates produced by this process are capable of absorbing carbon dioxide at high rates and in large amounts.
摘要:
Verfahren zur Herstellung eines Metalloxidpulvers mit einer BET-Oberfläche von mindestens 20 m 2 /g durch Reaktion eines Aerosols mit Sauerstoff in einem Reaktionsraum bei einer Reaktionstemperatur von mehr als 700°C und anschließender Abtrennung des erhaltenen Pulvers von den gasförmigen Stoffen, wobei - das Aerosol durch Verdüsen wenigstens eines Ausgangsmaterials, als solches in flüssiger Form oder in Lösung, und wenigstens eines Zerstäubungsgases mittels einer Mehrstoffdüse erhalten wird, - der volumenbezogene, mittlere Tropfendurchmesser D 30 des Aerosols 30 bis 100 µ m ist und - die Anzahl der Aerosoltropfen, welche größer als 100 µ m sind, bis zu 10% beträgt, bezogen auf die Gesamtanzahl der Tropfen. Mittels dieses Verfahrens erhältliches Metalloxidpulver.
摘要:
This invention relates to a process for preparing zirconium oxide, in its various forms, including zirconium-based mixed oxides. There is described a process for preparing a zirconium oxide in the absence of a cerium salt which comprises precipitating a zirconium hydroxide from an aqueous solution of a zirconium salt by reaction with an alkali in the presence of a controlled amount of sulphate anions at a temperature not greater than 50°C and then calcining the hydroxide to form an oxide, wherein the oxide thus formed is essentially sulphate free. Catalysts and ceramics can be produced from the product oxides having improved thermal stability and improved sinterability, respectively. A particular use of the product oxide is as a promoter or catalyst support in automobile exhaust systems.
摘要:
The method comprises treating the metallic nanoparticles with at least one stabilizing compound having at least one functional group selected from phosphoric and phosphonic acids and salts thereof, phosphine, phosphine oxide and phosphonium, whereby the dispersion is stable for at least one week.
摘要:
Die Erfindung betrifft ein Verfahren zur Herstellung eines feinteiligen Pulverwerkstoffs auf Zirkoniumoxid-Aluminiumoxid-Basis, insbesondere von ATZ- und/oder ZTA-Pulverwerkstoffen, bei dem Partikel aus in einem pulsierenden oder nicht-pulsierenden Heißgasstrom feinteilig eingesprühten gasförmigen, insbesondere dampfförmigen Rohstoff gebildet und anschließend in einem Filtersystem vom Heißgasstrom abgeschieden werden, wobei Aluminiumoxid-Partikel (Al 2 O 3 ) und dotierte Zirkoniumoxid-Paitikel (ZrO 2 ) getrennt nebeneinander im Pulver vorliegen.
摘要:
The present invention is directed to producing nano-structured particles that have high specific surface-areas and high thermal stability. By aging nanoparticle precursors, and processing them under appropriate conditions, one is able to generate nano-structured particles that may be used in catalysts. By adding a stabilizing agent one is able to further improve the high thermal stability. These nano-structured particle products are particularly advantageous in applications as catalysts or catalyst supports that operate at high temperatures.
摘要:
A sol comprising zirconium oxalate compound as a dispersoid, wherein the mol ratio of oxalic acid to Zr (oxalic acid/Zr) is from 1.2 to 3 and the particle diameter D50 of the dispersoid is from 10 to 100 nm. This sol is produced by adding oxalic acid to a dispersion liquid of zirconium hydroxide, wherein the addition of oxalic acid is carried out in two steps.