Gold supported on Ti incorporated MCM-36 as efficient catalysts in propylene epoxidation with H-2 and O-2

作者：Jin, Fang; Lin, Tsung-Han; Chang, Chih-Cheng; Wan, Ben-Zu; Lee, Jyh-Fu; Cheng, Soofin^*

来源：RSC Advances, 2015, 5(76): 61710-61718.

DOI：10.1039/c5ra08621c

• GAS-PHASE EPOXIDATION
• PROPENE EPOXIDATION
• ACTIVE-SITES
• TITANOSILICATE
• TITANIUM
• AU/TS-1
• SIZE
• NANOPARTICLES
• ENHANCEMENT
• ENSEMBLES

Novel catalysts consisting of gold nanoparticles (NPs) supported on the titanosilicate pillared MCM-36 (Si/TiMCM- 36) with 2 nm mesopores were prepared. The influences of the Ti coordination environment on the particle size of the anchored Au NPs and their catalytic performances in propylene epoxidation with mixtures of H-2 and O-2 were investigated. The catalyst materials were characterized with Electron Probe Micro Analysis, X-ray diffraction, nitrogen sorption, UV-visible diffuse reflectance spectroscopy, transmission electron microscopy, and X-ray absorption spectroscopy. The coordination environment of Ti(IV) in Si/Ti-MCM-36 was found to be a mixture of octahedral (O-h) and tetrahedral (T-d). The Au loading was proportional to the amount of Ti incorporated in the porous silica. The higher loading of Ti in Si/TiMCM-36 anchored more Au and resulted in the formation of larger Au particles. The deposition-precipitation (DP) with NH3 as a DP agent seemed to give Au NPs larger than those loaded by NaOH. The most efficient Au NPs size was about 1 nm, and Au NPs with sizes larger than 2 nm were not efficient for the propylene epoxide (PO) formation. By adjusting the Au and Ti synergy, the optimal PO formation rate over Au loaded Si/Ti-MCM-36 was 28.9 g(PO) h(-1) g(cat)(-1).

• 出版日期2015
• 单位武汉工程大学