Engineering the surface hydrophobicity of Au/TS-1 catalyst to promote the selective oxidation of propane

The selective oxidation of alkanes is challenging due to the inertness of C–H bonds and the tendency for overoxidation to COx. Metal-zeolite catalysts offer a promising solution by spatially decoupling oxygen and C–H bond activation on distinct active sites. This study introduces a strategy using surface hydrophobic modification of titanium silicalite-1 (TS-1) zeolites to achieve high selectivity in propane oxidation to acetone. Hydrophobic organosilanes with methyl groups were applied via a one-step co-condensation process, followed by Au nanoparticle immobilization. The hydrophobic groups prolong the residence time of the intermediate isopropanol on the catalyst surface, enhancing its conversion to acetone while stabilizing H 2 O 2 to prevent excessive oxidation of carbon-containing species into CO 2 during the process. The modified TS-1 demonstrated excellent thermal stability and selectivity, particularly under extreme hydrogen-to-oxygen ratios conditions. The alkylated Au/TS-1 catalysts significantly improved acetone production, providing a new pathway for selective alkane oxidation.