Gas-Phase Epoxidation of Propylene to Propylene Oxide on a Supported Catalyst Modified with Various Dopants

Catalysts

Tomoyasu Ogino¹  Naotaka Sakamoto¹  Naohiro Shimoda¹  Shigeru Sugiyama¹  Yasuhiro Sakuwa¹  Masahiro Katoh¹  Nobuhiro Kimura² 

[1] Department of Applied Chemistry, Graduate School of Technology, Industrial and Social Science, Tokushima University, Minamijosanjima, Tokushima-shi, Tokushima 770-8506, Japan;;Pilot Testing Group, Fuels Research Laboratory, Central Technical Research Laboratory, JXTG Nippon Oil &

关键词: epoxidation;    propylene;    propylene oxide;    Ag;    alkaline carbonates;   

DOI  :  10.3390/catal9080638

来源: DOAJ

【 摘 要 】

In the present study, the production of propylene oxide (PO) from propylene via gas-phase epoxidation was investigated using various catalysts. Although Ag is known to be a highly active catalyst for the epoxidation of ethylene, it was not active in the present reaction. Both Al and Ti showed high levels of activity, however, which resulted in confusion. The present study was conducted to solve such confusion. Although the employment of MCM-41 modified with Ti and/or Al was reported as an active catalyst for epoxidation, the combination resulted in the formation of PO at a less than 0.1% yield. Since this research revealed that the acidic catalyst seemed favorable for the formation of PO, versions of ZSM-5 that were both undoped and doped with Na, Ti, and Ag were used as catalysts. In these cases, small improvements of 0.67% and 0.57% were achieved in the PO yield on H-ZSM-5 and Ti-ZSM-5, respectively. Based on the results of the Ti-dopant and acidic catalysts, Ag metal doped on carbonate species with a smaller surface area was used as a catalyst. As reported, Ag‒Na/CaCO₃ showed a greater yield of PO at 1.29%. Furthermore, the use of SrCO₃ for CaCO₃ resulted in a further improvement in the PO yield to 2.17%. An experiment using CO₂ and NH₃ pulse together with SEM and TEM examinations for Ag‒Na/CaCO₃ revealed that the greatest activity was the result of the greater particle size of metallic Ag rather than the acid‒base properties of the catalysts.

【 授权许可】

Unknown