Enhancing the K-poisoning resistance of CeO2-SnO2 catalyst by hydrothermal method for NH3-SCR reaction

• Published in: Applied surface science Vol. 579; p. 152176
• Main Authors: Zhao, Wanxia, Rong, Jing, Luo, Wen, Long, Lulu, Yao, Xiaojiang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.03.2022
• Subjects: CeO2-SnO2; Hydrothermal method; NH3-SCR; Reaction mechanism; Resistance to K-poisoning; Reaction mechanism; CeO2-SnO2; NH3-SCR; Hydrothermal method; Resistance to K-poisoning
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2021.152176

[Display omitted] •CS-HT catalyst has better denitration performance and K-poisoning resistance.•The uniform distribution of Sn4+ in CeO2 increases oxygen vacancy of CS-HT catalyst.•Good surface acidity and redox performance improve K-poisoning resistance of CS-HT.•Both E-R and L-H mechanisms co-exist on CS-HT catalyst at high temperature. It is a very challenging task to improve the anti-alkali metal poisoning ability of non-vanadium-based denitration catalysts. To address this issue, we attempt to synthesize CeO2-SnO2 catalyst by hydrothermal method (denoted as CS-HT), which uses high temperature and high pressure environment of hydrothermal processto promote the distribution of Sn4+ in CeO2 lattice and enhance the interaction between each component. For comparison, CeO2-SnO2 catalyst was also prepared by co-precipitation method (denoted as CS-CP). The denitration activity and resistance to K-poisoning performance of these prepared catalysts for the selective catalytic reduction of nitrogen oxides by ammonia (NH3-SCR) were studied. The results showed that CS-HT catalyst had better denitration activity and anti-K poisoning performance than CS-CP catalyst. The physicochemical properties of these catalysts were characterized by XRD, Raman, XPS, H2-TPR, NH3-TPD. Experimental results indicated that the enhancement of anti-K poisoning ability of CS-HT catalyst was related to the good distribution of Sn4+, excellent redox performance and surface acidity. Moreover, the Sn-O bonds could combine with the introduced K more easily, which protected the Ce-O active sites. Finally, the possible NH3-SCR reaction mechanism and K-poisoning reasons on CeO2-SnO2 catalyst were analyzed by in-situ DRIFTS experiments.