Bio-inorganic hybrid catalyst combining enzyme aggregates and catalytic hollow spheres for the green epoxidation of olefins

In line with green chemistry principles, Vennestrom et al. proposed the chemoenzymatic epoxidation of olefins by sequential catalysis using glucose oxidase (GOx) - for in situ production of H2O2 - and microporous titanosilicalite-1 (TS-1). The direct immobilization of GOx on the catalyst was also proposed but the epoxide production was notably limited by the low enzyme loading. Here, we propose a new strategy for the preparation of a hybrid catalyst that combines all the features of TS-1 with a high loading of GOx. The method is based on the aerosol-assisted self-assembly of TS-1 nanocrystals to form hollow spheres with tailored texture and good epoxidation activity. These spheres are subsequently loaded with the enzymes which are then cross-linked to secure their entrapment. Upon optimization of the working conditions, we show that it is possible to reach much higher epoxide productivity.