Development of advanced zeolite catalysts for the vapor phase Beckmann rearrangement of cyclohexanone oxime

The vapor phase Beckmann rearrangement of cyclohexanone oxime to epsilon-caprolactam catalyzed by various zeolites was studied. The catalytic performance was greatly affected by both the zeolite structure and diluent solvent. When 1-hexanol was used in place of benzene, the catalytic performance of all catalysts except silicalite-1 was greatly improved. In particular, the selectivity and stability of H-LTL and H-OFF-ERI zeolites remarkably increased; both catalysts exhibited ca. 100% oxime conversion and epsilon-caprolactam selectivity of > 95% for 6 h. (C) 1997 Elsevier Science B.V.