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(cat)(-1) In this system, 10% conversion and 76% selectivity amount to a rate of 134 g(PO) h(-1) kg(cat)(-1), An optimal Au content that is support dependent is observed for these cat catalysts. © 2005 Elsevier Inc. All rights reserved.