| abstract |
Catalyst, in particular to produce phthalic anhydride through gas phase oxidation of o-xylene and / or naphalin, with an inert support and at least one layer applied on it, with a catalytically active mass containing TiO2, characterized in that at least a part of the TiO2 used has the following properties: (a) the BET surface is greater than 15 m² / g, (b) the primary grain size, determined by X-ray powder diffraction according to the Debye formula. Scherrer, is located at more than 210 angstroms and below 900 angstroms, where the D90 value of the TiO2 used is between 0.5 and 20 μm, the D50 value at 1.5 μm or below and less than 22% of the Total pore volume of the TiO2 used is formed through pores with a radius of more than 400 nm. |