Alkaline-Assisted\nExcessive Impregnation for Enhancing\nAu Nanoparticle Loading on the TS‑1 Zeolite

Direct epoxidation of propylene (C<sub>3</sub>H<sub>6</sub>) with\nhydrogen (H<sub>2</sub>) and oxygen (O<sub>2</sub>) over the Au/TS-1\ncatalyst is known as the “Holy Grail” reaction for propylene\noxide (PO) synthesis. However, Au nanoparticle loading on TS-1 was\nlimited by traditional deposition precipitation, impregnation and\ncould not achieve ideal catalytic results. In this report, alkaline-assisted\nexcessive impregnation helped to remove Cl<sup>–</sup> from\nthe Au impregnation precursor, improve the loading efficiency of Au\nnanoparticles and overcome the abnormal growth of nanograins. Better\nhydrophobicity, surface acidity and an oxygen-containing free radical\nenvironment helped Au/TS-1-AEI achieve much better C<sub>3</sub>H<sub>6</sub> conversion (8.0%), PO selectivity (96.7%) and stability (>100\nh).