CATALYST FOR OXIDATION OF O-XYLENE AND/OR NAPHTHALENE TO PHTHALIC ANHYDRIDE

摘要

Provided is a catalyst for the oxidation of o-xylene and/or naphthalene to phthalic anhydride, which has a plurality of catalyst zones which are arranged in series in the reaction tube and has been produced using an antimony trioxide which comprises a significant proportion of valentinite. Also disclosed is a process for gas-phase oxidation, in which a gas stream comprising at least one hydrocarbon and molecular oxygen is passed through a catalyst produced using an antimony trioxide which comprises a significant proportion of valentinite.