Synthesis strategy of atomically dispersed Au clusters induced by NH3 on TS-1: Significantly improve the epoxidation activity of propylene

•Au clusters smaller than 1.0 nm were synthesized on TS-1 molecular sieve.•NH3 improved the deposition rate and dispersion of Au.•14.3% of C3H6 conversion and 477.4 gPO·kgcat-1·h−1 PO productivity were obtained.•The catalytic mechanism under atomically dispersed Au clusters calculated by DFT.•The Ti-OOH structure formed in-situ was the key to catalytic epoxidation of C3H6.