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Indexed by:Journal Papers

Date of Publication:2019-08-25

Journal:APPLIED CATALYSIS A-GENERAL

Included Journals:EI、SCIE

Volume:584

ISSN No.:0926-860X

Key Words:catalysis; Au/TS-1; Propylene epoxidation; Pretreatment; H-2-C3H6

Abstract:Direct epoxidation of propylene (C3H6) with oxygen (O-2) and hydrogen (H-2) over gold catalysts is an efficient and environmentally benign process to produce propylene oxide (PO). Herein, Au/TS-1 was used to catalyze propylene epoxidation, and its pretreatment effect under different gas atmospheres was carefully investigated. The results showed that Au/TS-1 pretreated with H-2-C3H6 exhibited much better catalytic performance than that pretreated with single-component gas of H-2, O-2 and C3H6, dual-component gas of H-2-O-2 and O-2-C3H6, and feed gas of H-2 + O-2 + C3H6. UV/vis/NIR spectra, O-2-TPO-MS and Si-29 NMR indicated that the pretreatment of Au/TS-1 using H-2-C3H6 led to hydrophobic catalyst surfaces functionalized by hydrocarbon species, consequently facilitating the C3H6 adsorption and PO desorption. HAADF-STEM showed that H-2-C3H6 pretreatment caused the formation of small Au nanoparticles (NPs) with an average size of (similar to)2.1 nm. The common effect of small Au NPs and hydrophobic surface was speculated to be responsible for the excellent catalytic performance of Au/TS-1 pretreated with H-2-C3H6.