Beckmann rearrangement of cyclohexanone oxime over mesoporous Si-MCM-41 and Al-MCM-41 molecular sieves

Abstract

Si-MCM-41 and Al-MCM-41 with different Al contents (Si/Al = 43.9, 23.3 and 14.3) have been prepared using cetyl trimethylammonium bromide as an organic surfactant and characterised by XRD, MAS NMR and N2 sorption studies. The transformation of cyclohexanone oxime into ε-caprolactam has been studied over these molecular sieves. The influences of temperature and feed rate (WHSV) on the yield of caprolactam over the samples have been investigated at different times on stream. The studies reveal that activity and selectivity increase with Al content (investigated upto Si/Al = 14) and maximum yield of ε-caprolactam is obtained at ∼360 ◦C.