Three-Dimensional Hierarchical Hydrotalcite–Silica Sphere Composites as Catalysts for Baeyer–Villiger Oxidation Reactions Using Hydrogen Peroxide

Abstract

The development of effective, environmentally friendly catalysts for the Baeyer–Villiger reaction is becoming increasingly important in applied catalysis. In this work, we synthesized a 3D composite consisting of silica spheres coated with Mg/Al hydrotalcite with much better textural properties than its 2D counterparts. In fact, the 3D solid outperformed a 2D-layered hydrotalcite as catalyst in the Baeyer–Villiger reaction of cyclic ketones with H2O2/benzonitrile as oxidant. The 3D catalyst provided excellent conversion and selectivity; it was also readily filtered off the reaction mixture. The proposed reaction mechanism, which involves adsorption of the reactants on the hydrotalcite surface, is consistent with the catalytic activity results.