Beckmann rearrangement of cyclohexanone oxime over mesoporous MCM-41- and MCM-48-type materials

摘要

The Beckmann rearrangement of cyclohexanone oxime in the gas phase has beeninvestigated over siliceous MCM-41- and MCM-48-type materials. At 275 ℃ completeconversion occurs for several hours with selectivities for ε-caprolactam up to 65 %, until thecatalysts deactivate rapidly. The deactivation of the mesoporous catalysts is considerablyreduced as compared to that obtained over an amorphous silica gel. MCM-48 exhibits thehighest catalyst lifetime which, for MCM-41-type materials, is longer with larger porediameter. With an aluminum-containing H-MCM-41 catalyst an increased ε-caprolactamselectivity is achieved.