Abstract:
Bei einem Verfahren zur Aufarbeitung eines Rohesters, der Veresterungskatalysator- Hydrolyseproduktin suspendierter partikulärer Form enthält, wird a) der Rohester in einem Emulgier-Kessel mit 1 bis 10 Gew.-% Wasser versetzt und das Wasserunter Erhalt einer Suspo-Emulsion im Rohester emulgiert, b) die Suspo-Emulsion aus dem Emulgier-Kessel in einen Agglomerier-Kessel mit vorgelegtem, Wasser-untersättigten Rohester überführt, so dass sich im Gemisch der Suspo-Emulsion und des vorgelegten Rohesters ein Wassergehalt unterhalb der Löslichkeitsgrenze von Wasser im Rohester einstellt, wodurch die suspendierten partikulären Veresterungskatalysator- Hydrolyseprodukte stabile Agglomerate ausbilden, und c) die gebildeten Agglomerate werden abfiltriert.
Abstract:
The present invention relates to a process for the production of mixed oxide particles comprising: (1) providing a dispersion comprising a disperse phase and a continuous phase, wherein the disperse phase comprises one or more precursor compounds of ceria, one or more precursor compounds of zirconia, and one or more precursor compounds of one or more rare earth oxides other than ceria and/or one or more precursor compounds of yttria; (2) forming an aerosol of the dispersion provided in step (1); and (3) pyrolyzing the aerosol of step (2) to obtain mixed oxide particles, as well as to mixed oxide particles obtainable from flame spray pyrolysis, and preferably obtain- able by the inventive process and to its use.
Abstract:
Provided are processes for the production of particles of catalytic material for emissions control obtainable in one-step from flame spray pyrolysis of precursor-containing dispersion(s), the method comprising: (1) providing a dispersion comprising one or more disperse phases and a continuous phase, the dispersion comprising: (a) a precursor compound of a first platinum group metal and a precursor compound of a first support, and (b) a precursor compound of a second platinum group metal and a precursor compound of a second support, wherein (a) is in a first phase that is different from a second phase containing (b); (2) forming an aerosol of the dispersion provided in step (1); and (3) pyrolyzing the aerosol of step (2) to obtain the particles of catalytic material. The catalytic particles comprise more than one support material and more than one platinum group metal, for use as, for example, three-way conversion (TWC) catalysts.