Vapor phase Beckmann rearrangement of cyclohexanone oxime over metal pillared ilerite

The vapor phase Beckmann rearrangement of cyclohexanone oxime to -caprolactam has been studied using various metal pillared ilerites (M-ilerite) as catalysts. Ta- and Nb-ilerite exhibited high catalytic activities for the vapor phase Beckmann rearrangement. The oxime conversion over Ta-ilerite reached up to 98.9% with the lactam selectivity of 96.7% at 350°C. FT-IR and NH₃-TPD results revealed that the excellent catalytic performance of Ta- and Nb-ilerite should be ascribed to a large number of hydroxyl groups of the catalyst and their relatively weak acidity.