Titanosilicalite-1 (TS-1) was first treated with aqueous KOH solution to introduce surface defects. Then KOH-treated TS-1 (TS-1K) was further treated with aqueous HNO3 solution to remove residual potassium. Then, Au was deposited by solid grinding on this support free of K (TS-1KH) as 1.6 nm clusters, which could be stabilized by surface detects. Finally, Au/TS-1KH was modified by impregnating potassium salts, alkali hydroxides or alkaline earth metal acetates. XRD and UV-vis spectra indicated that the crystalline MFI structure and 4-fold coordinated Ti4+ sites of TS-1 were maintained even after different treatments. HAADF-STEM showed that after the modification of Au/TS-1-KH the mean diameter of Au clusters increased only slightly from 1.6 nm to 1.8 nm. In propene epoxidation with molecular 02 and H2O, Au/TS-1KH promoted by basic potassium salts (CH3COO-, CO32- and PO43-) or hydroxides of Na, K, Rb and Cs could produce PO with the selectivity of 12-45%, while Au/TS-1KH combined with neutral potassium salts (KCI, KNO3 and K2SO4), LiOH or alkaline earth metal acetates could not produce PO. (c) 2012 Elsevier BM. All rights reserved.