Abstract:
Ceria-Zirconia-Mixed oxide particles and process for their production by pyrolysis, wherein the process comprising: (1) providing a mixture comprising a solvent, 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 mixture provided in step (1); and (3) pyrolyzing the aerosol of step (2) to obtain mixed oxide particles; wherein the content of the rare earth oxides other than ceria and/or of yttria in the mixed oxide particles formed in step (3) is comprised in the range of from 0.1 to 4.9 wt.-% based on the total weight of the rare earth oxides, yttria, and zirconia contained in the mixed oxide particles, as well as to mixed oxide particles obtainable from flame spray pyrolysis and to their use as an oxygen storage component, a catalyst and/or as a catalyst support.
Abstract:
The invention relates to a method for producing a catalyst comprising 0.05 - 0.25 wt % of noble metal, preferably for the oxidative dehydration of olefinically unsaturated alcohols, comprising the following steps: a) generating a direct current plasma, b) introducing metal and carrier material into the plasma, c) vaporizing metal and carrier material in the plasma or "blasting" the solid body of metal and carrier material in the plasma, and reacting the particles, d) cooling, wherein very small particles of composite material are obtained, and e) applying the composite material to the actual catalyst carrier. The invention further relates to a correspondingly produced catalyst, and to the use thereof.
Abstract:
The invention relates to a method for producing acetylene according to the Sachsse-Bartholome method by burning a natural gas/oxygen mixture in one or more burners, yielding a cracked gas, which is cooled in burner columns in two or more stages, wherein one or more burner columns are assigned to each burner, and wherein the cracked gas is quenched with pyrolysis oil in the first cooling stage, yielding a low-boiling fraction containing benzene, toluene and xylene from the one or more burner columns, wherein said fraction is cooled with direct cooling water and separated in a phase separator into an aqueous phase and an organic phase which contains benzene, toluene and xylene and is fully or partially fed back to the head of the one or more burner columns. The method is characterised in that the organic phase containing benzene, toluene and xylene from the phase separator, before full or partial recirculation to the head of the one or more burner columns, is fed to a selective hydrogenation process on a catalyst, which comprises at least one platinum group metal on an inorganic metal oxide carrier, containing 0.05 to 5 wt % of platinum group metal, relative to the total weight of the catalyst, and wherein the selective hydrogenation is carried out at a pressure in the range of 10 to 70 bar overpressure and a temperature in the range of 0 to 100°C.