Hybrid Chemo-Biocatalysts Prepared in One Step from Zeolite Nanocrystals and Enzyme-Polyelectrolyte Complexes

Abstract

The combination of heterogeneous catalysts and enzymes, in so-called hybrid catalysts, is an attractive strategy to effectively run chemoenzymatic reactions. Yet, the preparation of such bifunctional materials remains challenging because both the inorganic and the biological moieties must be integrated in the same solid, while preserving their intrinsic activity. Combining an enzyme and a zeolite, for example, is complicated because the pores of the zeolite are too small to accommodate the enzyme and a covalent anchorage on the surface is often ineffective. Herein, we developed a new pathway to prepare a hybrid catalyst built from glucose oxidase and TS-1 zeolite. Such hybrid material can catalyze the in situ formation of H2O2, which is subsequently used by the zeolite to trigger the epoxidation of allylic alcohol. Starting from an enzymatic solution and a suspension of zeolite nanocrystals, the hybrid catalyst is obtained in one step, using a continuous spray drying method. While enzymes are expectedly unable to resist the conditions used in spray drying (temperature, shear stress, etc.), we leverage on the preparation of “enzyme-polyelectrolyte complexes” (EPCs) to increase the enzyme stability. Importantly, the use of EPCs also appears to prevent enzyme leaching and to stabilize the enzyme against pH changes. We show that the one-pot preparation by spray drying gives access to hybrid catalysts with unprecedented performance in the targeted chemoenzymatic reaction. Interestingly, the hybrid catalyst performs much better than the two catalysts operating as separate entities. We anticipate that this strategy could be used as an adaptable method to prepare other types of multifunctional materials.<br>