The vapor-phase Beckmann rearrangement of cyclohexanone oxime to ε- caprolactam was examined over a variety of TiO2-ZrO2 mixed oxides modified by addition of sulfate, phosphate, and oxides of molybdenum, tungsten as well as boron. The catalytic reactions were performed in a continuous folw fixed-bed micro-reactor under atmospheric pressure. Boron oxide (B2O3) modified TiO2-ZrO2(B2O3/TiO2-ZrO2) showed the highest selectivity (97.0%) and yield(96.7%) of ε-caprolactam among the catalysts examined. Thses catalysts were characterized by nitrogen adsorption and temperature- programmed desorption of ammonia and carbon dioxide techniques. The effect of the physio-chemical properties of these catalysts on their catalytic performance was examined. The catalytic properties of B2O3/TiO2-ZrO2 were better than those of B2O3/TiO2 and B2O3/ZrO2.

Key words: CATALYTIC ACTIVITY, CYCLOHEXANONE-OXIME, GAS PHASE REACTION, TITANIUM COMPOUNDS, ZIRCONIUM COMPOUNDS, BORON OXIDE, CAPROLACTAM, BECKMANN REARRANGEMENT