Liang Yanli, Huang Yufen, Zhang Hailong, Lan Li, Zhao Ming, Gong Maochu, Chen Yaoqiang, Wang Jianli
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University, Wangjiang Road 29, Chengdu, Sichuan, 610064, China.
Environ Sci Pollut Res Int. 2017 Apr;24(10):9314-9324. doi: 10.1007/s11356-017-8645-x. Epub 2017 Feb 23.
To preferably catalyze the oxidation of NO to NO in diesel after-treatment system, a series of CeO-MnO composite oxides was supported on silica-alumina material by the co-impregnation method. The maximum conversion of NO of the catalyst with a Ce/Mn weight ratio of 5:5 was improved by around 40%, compared to the supported manganese-only or cerium-only sample. And its maximum reaction rate was 0.056 μmol g s at 250 °C at the gas hourly space velocity of 30,000 h. The experimental results suggested that Ce-Mn solid solution was formed, which could modulate the valence state of cerium and manganese and exhibit great redox properties. Moreover, the strong interaction between ceria and manganese resulted in the largest desorption amount of strong chemical oxygen and oxygen vacancies, leading to the maximum O area ratio of 62.26% from the O 1s result. These effective oxygen species could be continually transferred to the surface, leading to the best NO catalytic activity of 5Ce5Mn/SA catalyst. Graphical abstract.
为了在柴油后处理系统中更好地催化NO氧化为NO，采用共浸渍法将一系列CeO-MnO复合氧化物负载在硅铝材料上。与仅负载锰或仅负载铈的样品相比，Ce/Mn重量比为5:5的催化剂的NO最大转化率提高了约40%。在250℃、气体时空速为30000 h的条件下，其最大反应速率为0.056 μmol g s。实验结果表明，形成了Ce-Mn固溶体，它可以调节铈和锰的价态并表现出良好的氧化还原性能。此外，二氧化铈和锰之间的强相互作用导致强化学氧和氧空位的最大脱附量，从O 1s结果来看，导致最大O面积比为62.26%。这些有效的氧物种可以不断转移到表面，从而使5Ce5Mn/SA催化剂具有最佳的NO催化活性。图形摘要。
