Understanding the role of Al2O3-ZrO2 mixed oxides as support for vanadium catalysts for the selective ammoxidation of o-chlorotoluene to o-chlorobenzonitrile

• Al 2 O 3 -ZrO 2 supported V 2 O 5 catalysts are active for ammoxidation of o-chlorotoluene. • The ammoxidation activity related on the type of vanadium species present on mixed oxide support. • Mixed oxide support favors the well dispersion and stabilization of V 2 O 5 . • The catalysts are near 100% selective to o‑chloro benzonitrile with high stability. o -Chlorotoluene ( o -CT) ammoxidation to prepare o -chlorobenzonitrile ( o -CBN) was investigated on Al 2 O 3 -ZrO 2 supported V 2 O 5 catalysts in the temperature range of 360 to 420 °C. A set of vanadium oxide supported on mixed oxides with varying its loadings were prepared by wet impregnation method. The catalysts surface and structural characteristics were derived from BET-surface area, X-ray diffraction, FT-infrared, temperature programmed reduction, temperature programmed desorption of ammonia and UV–Vis diffuse reflectance spectroscopy. The characterization results revealed that vanadium species were well dispersed and strongly interacted with mixed oxide support. The ammoxidation activity was depended on V 2 O 5 content and its nature of surface species existing in the catalyst. The catalyst with 10 wt% of V 2 O 5 on Al 2 O 3 -ZrO 2 showed high ammoxidation activity with 100% selectivity to o-CBN. Moreover, the catalyst showed consistent activity during time on stream study.