Organic groups-regulated high-efficiency catalysis of hybrid Ti-Containing mesoporous silicates for Bi-Phase interfacial epoxidation

Abstract

The sluggish interfacial mass transfer usually hinders the achievement of high-efficiency catalytic transformation of biomass, especially for solvent-free immiscible reagent systems. Herein, amphiphilic hybrid Ti-containing catalysts in situ incorporated with organic groups (Cn-Ti-HMS) were developed for boosting biphasic solvent-free epoxidation of methyl oleate (MO) with H2O2. Benefiting from the mutual effect between organic/inorganic precursors, the resulting low-defect catalysts exhibit well-mediated surface hydrophilic/hydrophobic balance and porosity by incorporating alkyl groups. Such mediation effect exhibits two superiorities: i) accelerated adsorption of reactants by amphiphilicity; ii) boosted substrate or product diffusion by porosity property. As such, remarkably promoted catalytic properties were achieved when compared with conventional Ti-HMS. Typically, methyl-functionalized C1–Ti-HMS-50 displays the optimal catalytic performance with a 95% conversion of MO. Further mechanism study recognizes the dominant role of surface wettability and Si–OH defects content in influencing MO conversion and epoxidized MO selectivity.