Gas-phase epoxidation of propylene through radicals generated by silica-supported molybdenum oxide
Gas-phase epoxidation of propylene through radicals generated by silica-supported molybdenum oxide
复制标题
DOI：
10.1016/j.apcata.2006.08.029
复制
发表时间：
2007-01
影响因子：
5.5
通讯作者：
Zhaoxia Song;N. Mimura;Juan J. Bravo-Suárez;T. Akita;S. Tsubota;S. Oyama
中科院分区：
文献类型：
--
作者：
Zhaoxia Song;N. Mimura;Juan J. Bravo-Suárez;T. Akita;S. Tsubota;S. Oyama
研究发现，在各种二氧化硅负载的金属氧化物中，二氧化硅负载的氧化钼对于丙烯的环氧化是非常有效的。后催化床体积对其形成起着重要作用。在0.255mmol/g-SiO2的MoOx/SiO2上，在5atm、573K和C3H6/O2/He=10/5/10cm3min−1的流速下获得17.6%的丙烯转化率和43.6%的PO选择性。表征研究表明，结晶 MoO3 纳米颗粒物质比分子分散的氧化钼物质对于丙烯环氧化成 PO 更有效。假设 MoOx/SiO2 催化剂上丙烯环氧化的反应机理涉及分散的氧化钼物质在相对较低的温度下产生的气相自由基。这些自由基参与与分子氧的均相反应，生成环氧丙烷。
It was found that silica-supported molybdenum oxide was high effective for the epoxidation of propylene among various silica-supported metal oxides. The post-catalytic bed volume played an important role in its formation. On a MoOx/SiO2with 0.255mmol/g-SiO2, a propylene conversion of 17.6% and a PO selectivity of 43.6% were obtained at 5atm, 573K and flow rates of C3H6/O2/He=10/5/10cm3min−1. The characterization studies indicated that crystalline MoO3nano-particle species was more effective for propylene epoxidation to PO than molecularly dispersed Mo oxide species. The reaction mechanism of propylene epoxidation on MoOx/SiO2catalysts is hypothesized to involve gas-phase radicals generated at relatively low temperature by the dispersed molybdenum oxide species. These radicals participated in homogeneous reactions with molecular oxygen to produce propylene oxide.