Water‐Tolerant, Highly Active Solid Acid Catalysts Composed of the Keggin‐Type Polyoxometalate H₃PW₁₂O₄₀ Immobilized in Hydrophobic Nanospaces of Organomodified Mesoporous Silica

High activity in tight spaces: Polyoxometalate H3PW12O40 surrounded by hydrophobic alkyl groups in the channels of mesoporous silica (see picture) showed exceptionally high catalytic activity for ester hydrolysis in water. The nanostructure based on mesoporous silica allows the aqueous reaction mixture to easily reach the active sites, despite their being surrounded by hydrophobic moieties.