Synthesis of titanium silicalite-1 with high titanium content and its catalytic performance of propylene epoxidation

Titanium silicalite-1 (TS-1) has unique catalytic properties for oxidation reactions due to the titanium atom in the framework. To increase the Ti content in the framework, polyvinylpyrrolidone (PVP) was added as a surfactant to modify TS-1 (PTS-1). The titanium content in PTS-1 as the active site in the catalytic reaction increased to 0.87 wt%, compared with the traditional TS-1 which has a titanium content of 0.64 wt%. Simultaneously, the average particle size of PTS-1 is reduced to 180 nm, compared with TS-1 (230 nm). The increase in Ti content makes the Au loading increase; thus, Au/PTS-1 shows higher catalytic performance for propylene epoxidation, and the propylene oxide (PO) formation rate increases from 95 g PO h −1 kg Cat −1 with Au/TS-1 to 190 g PO h −1 kg Cat −1 with Au/PTS-1. In addition, the mechanism for the modification of Ti content by PVP is proposed.