INVESTIGATION OF THE OXIDATION OF O-XYLENE OVER A VANADIA TITANIA CATALYST BY MEANS OF THE TAP REACTOR/

The oxidation of o-xylene over a commercial V2O5/TiO2 (anatase) cataly st was studied in the TAP (Temporal Analysis of Products) reactor syst em. The transient method with high time resolution has led to new insi ghts into the reaction mechanism. The selective oxidation is shown to consist of a sequence of steps, involving intermediates which desorb a s o-toluotaldehyde and phtalide. The key reaction step in the non-sele ctive oxidation is shown to be a decarbonylation of a surface species, leading to a surface benzoate. The kinetics of the elementary steps i n the reaction were derived from a quantitative analysis of the transi ent responses on o-xylene pulses.