1. Mn and Fe oxides co-effect on nanopolyhedron CeO2 catalyst for NH3-SCR of NO.
- Author
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Zhou, Yuhan, Ren, Shan, Wang, Mingming, Yang, Jie, Chen, Zhichao, and Chen, Lin
- Subjects
CERIUM oxides ,CATALYSTS ,CATALYTIC activity ,RAMAN spectroscopy ,MANGANESE oxides - Abstract
The active components Mn and Fe oxides were loaded on the surface of CeO 2 catalyst with nanopolyhedrons morphology (CeO 2 -NPs) by impregnation method to improve the CeO 2 -NPs catalyst catalytic performance. The activity test results showed that the activity order of these catalysts within the temperature of 100–300 °C was Fe-Mn-Ce > Mn-Ce > Ce catalyst, and the NO conversion rate of Fe-Mn-Ce catalyst was the highest at 200 °C, which was about 98%. The performances of these catalysts were further investigated by SEM, XRD, XPS, Raman spectra, H 2 -TPR, NH 3 -TPD and in situ DRIFT. The results indicated that Fe-Mn-Ce catalyst possessed the best reducibility and surface acidity of the three catalysts. According to the XPS and Raman spectra tests, the sequences of the ratio of O α /(O α +O β) and Ce
3+ /(Ce3+ +Ce4+ ) were both Fe-Mn-Ce > Mn-Ce > Ce catalyst, which indicated that the Fe-Mn-Ce catalyst possessed the most oxygen vacancy and further improved the catalytic activity of the catalyst. Moreover, the Fe-Mn-Ce catalyst also exhibited the best tolerance to SO 2 of the three catalysts at 225 °C. In general, simultaneous loading of manganese and iron oxides on the CeO 2 -NPs catalyst could effectively improve the low temperature SCR performance of the catalyst. • Fe-Mn-Ce catalyst showed superior catalytic activity at low-temperature. • Fe-Mn-Ce catalyst had more oxygen vacancies. • Fe-Mn-Ce catalyst could increase the relative ratios of surface adsorbed oxygen. • Fe-Mn-Ce catalyst possessed the best reducibility and surface acidity. [ABSTRACT FROM AUTHOR]- Published
- 2021
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