Vapor-phase Beckmann rearrangement of cyclohexanone oxime over modified titania-zirconia catalyst

The vapor - phase Beckmann rearrangement of cyclohexanone oxime to E-caprol actam was examined over a variety of TiO2 - ZrO2 mixed oxides modified by a ddition of sulfate, phosphate, and oxides of molybdenum,tungsten as well as boron. The catalytic reactions were performed in a continuous now fixed - bed micro - reactor under atmospheric pressure. Boron oxide (B2O3) modified TiO2 - ZrO2 (B2O3/TiO2 - ZrO2) showed the highest selectivity(97.0%) and y ield(96.7%) of epsilon - caprolactam among the catalysts examined. These ca talysts were characterized by nitrogen adsorption and temperature - program med desorption of ammonia and carbon dioxide techniques. The effect of the physio - chemical properties of these catalysts on their catalytic performa nce was examined. The catalytic properties of B2O3/TiO2 - ZrO2 were better than those of B2O3/TiO2 and B2O3/ZrO2.