Green synthesis of MCM-41 from rice husk and its functionalization with nickel(II) salen complex for the rapid catalytic oxidation of benzyl alcohol

N,Nʹ-bis(4-hydroxysalicylidene)ethylenediamine nickel(II) complex was synthesized and functionalized onto MCM-41. The catalyst denoted as MCMSalenNi, was found to retain its hexagonal mesoporous structure as indicated from the TEM images. It however, had a reduced surface area and lower x-ray diffraction intensity than the parent MCM-41. Both FT-IR and solid-state MAS NMR (29Si, 13C) analyses proved that the complex was successfully functionalized onto the MCM-41 support. The catalyst was used in the rapid oxidation of benzyl alcohol and it afforded a high conversion (~98%) with benzaldehyde as the major product within 90 min. Periodic acid was used as a mild oxidant. In addition, the catalyst was reused up to six times with minimal loss of activity. [Display omitted] •Ni(4-OH)2 salen complex was synthesized and functionalized onto MCM-41 using CPTES.•The hexagonal honey-comb structure of MCM-41 was maintained after functionalization.•Approximately 98.4% conversion of benzyl alcohol was obtained within 90 min.•MCMSalenNi showed immense stability upon successive reuse up to six cycles.