期刊
ACS CATALYSIS
卷 9, 期 8, 页码 6698-6710出版社
AMER CHEMICAL SOC
DOI: 10.1021/acscatal.9b01324
关键词
toluene oxidation; spinel CoMn2O4; oxygen species; in situ designed-TP techniques; in situ DRIFTS
资金
- National Nature Science Foundation of China [21876019, 21806017]
- Programme of Introducing Talents of Discipline to Universities [B13012]
- State Key Laboratory of Catalysis in DICP [Y401010502]
The catalytic oxidation of toluene to CO2 and H2O over nanoflower spinel CoMn2O4, synthesized by the oxalic acid sol-gel method has been investigated, and it demonstrates lower activation energy (35.5 kJ/mol) for toluene oxidation compared with that using the metal oxides (Co3O4, MnOx and Co3O4/MnOx), which shows nearly 100% conversion of toluene at 220 degrees C in the presence or absence of water vapor (2.0 vol %). Compared with the metal oxides (Co3O4/MnO MnOx, and Co3O4), the obtained spinel CoMn2O4 has a larger surface area, rich cationic vacancy, and high mobility of oxygen species, which are the reasons for its high activity for toluene oxidation. The different oxygen species shows the different role in VOCs oxidation, and the in situ designed-TP techniques are conducted to investigate the involvement of surface lattice oxygen, bulk lattice oxygen, and gaseous oxygen in catalytic oxidation of toluene over the spinel CoMn2O4 and Co3O4/MnOx catalysts. For spinel CoMn2O4, the surface lattice oxygen is the reactive oxygen species, which first induces the catalytic reaction. Furthermore, the gaseous oxygen moves to the bulk phase lattice and then migrates to the surface to form the surface lattice oxygen, which is different from the mixed-metal oxides Co3O4/MnOx that dissociates and activates gaseous oxygen only on the surface of the catalyst and requires a higher temperature. In addition, it is found that the toluene oxidation occurs via the benzyl alcohol benzoate anhydride acetate reaction pathway over spinel CoMn2O4, and the conversion of the surface anhydride is the rate-controlling step, especially at 200-210 degrees C, which is also different from the mixed-metal oxides Co3O4/MnOx, These results could provide a considerable experimental basis for understanding the mechanism by which oxygen species participate in toluene oxidation.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据