TS-1/spherical activated carbon composites in the epoxidation of methyl oleate†
Abstract
One approach to increase the catalytic efficiency of TS-1 is the synthesis of TS-1 composite materials together with spherical activated carbon (SAC). Although increased Ti-site normalized catalytic activity of such composites compared to parent materials was observed, the reason for the increased activity is not fully understood. This study therefore aims to correlate the physico-chemical and catalytic activity of TS-1/SAC composites. Composite materials with different TS-1 weight fractions were prepared and applied in the heterogeneously catalyzed epoxidation of methyl oleate using aqueous H2O2. Up to seven times greater Ti-site normalized activity for the composites was observed compared to the parent TS-1. The pulsed field gradient (PFG) NMR was then used to rationalize the catalytic activity results. SAC was found to function similarly to a conventional catalyst support (e.g., in supported metal catalysts) for the TS-1. The SAC thus allows control of the dispersion of and pore space arrangement between TS-1 crystals, which could be directly linked to an increase in catalytic activity. In addition to gaining insight into the fundamental principles of such composite catalysts, the importance of the sorption of reactant and product molecules on the catalytic activity was pointed out.