Construction of hierarchical Sn-ECNU-7 zeolite with MWW nanosheets for Baeyer-Villiger oxidation of bulky reactant

Abstract

The Baeyer-Villiger (BV) oxidation which can transform ketones into the corresponding lactones attracts wide attention. Although many Sn-containing zeolites have shown superior activity, bulky reactants often suffer low mass transfer efficiency during BV reaction due to the narrowed channel opening of microporous zeolite catalysts. To address this issue, we developed a preparation method to construct the swollen-type Sn-MWW zeolite, namely Sn-ECNU-7P, in which cetyltrimethylammonium bromide (CTAB) surfactant successfully swollen the adjacent MWW nanosheets with a large interlayer spacing of 22 Å during hydrothermal synthesis. The subsequent of acid treatment and calcination led to the formation of a hierarchical porous system in the resulting Sn-ECNU-7 zeolite with a high external surface area. Compared to conventional Sn-MWW catalysts, Sn-ECNU-7 exhibited a higher activity and stability for the BV oxidation reaction of bulky 2-adamantanone using H2O2 and tert-butyl hydroperoxide (TBHP) as oxidants, showing a promising potential for the application in BV oxidation of bulky reactants.