Highly efficient and reusable Cu-MCM-41 catalyst for the Baeyer–Villiger oxidation of cyclohexanone

• Cu-MCM-41 was firstly applied in the Baeyer–Villiger oxidation of cyclohexanone.
• 99.0% conversion of cyclohexanone was achieved with 2 molar equiv of benzaldehyde.
• Isolated Cu2 + species in Cu-MCM-41 were active sites.
• Cu-MCM-41 showed good recyclability.

A series of Cu-MCM-41 with different Cu contents were successfully synthesized by the direct hydrothermal (DHT) method and evaluated in the Baeyer–Villiger oxidation of cyclohexanone, using only 2 molar equiv of benzaldehyde as sacrificial agents. High conversion (99.0%) of cyclohexanone and ε-caprolactone selectivity (100%) were detected over Cu-MCM-41 (23) within 3 h. Various physical–chemical characterizations, including BET, XRD, UV–vis and H2-TPR, revealed that isolated Cu2 + species in the MCM-41 framework were responsible for the catalytic activities. This catalyst could be reused for three times without discernible loss in its activity and selectivity.