Vapor phase Beckmann rearrangement of cyclohexanone oxime over different ferrierite zeolite catalysts

Ferrierite zeolite catalysts prepared using different procedures have been tested for their activity for vapor phase Beckmann rearrangement of cyclohexanone oxime to c-caprolactam. We report here the results of a study seeking the influence of temperature, nitrogen feed rate, oxime concentration and solvents on the catalyst performance. At low concentration of oxime (2.5 wt%), using acetonitrile as solvent the maximum in the conversion of oxime and selectivity to c-caprolactam has been obtained. The presence of weak, medium and strong acid sites as indicated by temperature-programmed desorption of NH3 corroborates well with the catalytic activities of various ferrierites shown here. Solvent polarity is found to significantly affect the conversion of cyclohexanone oxime.