Vapor-Phase Beckmann Rearrangement of Cyclohexanone Oxime over an HY Zeolite Catalyst Calcined at High Temperature

Article abstract of DOI:10.1246/bcsj.65.1486

The vapor-phase Beckmann rearrangement of cyclohexanone oxime over an HY zeolite calcined at high temperature was investigated.Cyclohexanone oxime was rearranged into ε-caprolactam with high conversion at 573 K over an HY zeolite calcined at 873 K.The activity decay was slight, while oxime conversion over an HY zeolite calcined at 773 K steeply decreased during the initial stage of the reaction.The catalytic activity for the rearrangement was not correlated with the physical properties of a fresh catalyst, but with those of a used one, especially regarding their porosity and acidity.It was also found that the produced ε-caprolactam was tightly adsorbed on strong acid sites, filling the micropores of the zeolite during the initial stages of the reaction, and that a large portion of the catalytic reaction proceeded mainly on weak acids sites located in a region near to the external surface of the zeolite.