Modification of Au/TS-1 catalysts with cobalt resulted in a strong increase in the formation rate of propene oxide in the direct gas-phase propene epoxidation using a H-2/O-2 mixture as oxidant. A detailed investigation of these Au-Co/TS-1 catalysts by means of ICP, XPS, TEM and microcalorimetry revealed that this effect is mainly due to the higher gold uptake during deposition precipitation. In contrast to TiO2 supported gold catalysts with a similar metal content, Au-Co/TS-1 showed an extraordinary stability in terms of deactivation at a low reaction temperature of 125 degrees C not reported before.