Enhancement of Au capture efficiency and activity of Au/TS-1 catalysts for propylene epoxidation

A method for enhancing the useful Au content in Au/TS-1 catalysts for vapor-phase propylene epoxidation is reported. Exposure of calcined TS-1 support to 1 M NH4NO3 at 80 °C, followed by vacuum drying, produced a modified TS-1 support material. Deposition precipitation of gold on these modified TS-1 supports resulted in a fourfold increase in Au capture efficiency and produced catalysts with 5-10% conversion of propylene with 75-85% selectivity for PO, at 200 °C and a space velocity of 7000 ml h−1 g−1cat. In this system, 10% conversion and 76% selectivity amount to a rate of 134 gPO h−1 kg−1cat. An optimal Au content that is support dependent is observed for these catalysts.