Study of the selectivity of a V2O5−ZrO2 catalyst for partial oxidation ofo-xylene at high temperatures

It has been established that at high temperatures (above 450°C) the V2O5−ZrO2 catalyst exhibits a higher selectivity in the oxidation ofo-xylene to phthalic anhydride than does the conventional V2O5−TiO2(a) catalyst. The catalyst selectivity is found to increase with respect to partial oxidation ofo-xylene, the valuable by-product maleic anhydride being obtained. Studies by different physicochemical methods have shown that V2O5−ZrO2 undergoes no significant phase and structural changes under high-temperature conditions.