Influence of CeO₂ loading on structure and catalytic activity for NH₃-SCR over TiO₂-supported CeO₂

Hongliang Zhang^1,2,3，Long Ding¹，Hongming Long^1,2，Jiaxin Li^1,2，Wei Tan⁴，Jiawei Ji⁴，Jingfang Sun⁴，Changjin Tang⁴，Lin Dong⁴

1. School of Metallurgical Engineering,Anhui University of Technology2. Key Laboratory of Metallurgical Emission Reduction & Resources Recycling (Anhui University of Technology),Ministry of Education3. Analysis and Testing Central Facility,Anhui University of Technology4. Jiangsu Key Laboratory of Vehicle Emissions Control,School of Chemistry and Chemical Engineering,Nanjing University

摘 要：A series of supported CeO₂/TiO₂ catalysts were prepared to explore the influence of CeO₂ loading on these catalysts for the selective catalytic reduction of NO₃ by NH₃（NH₃-SCR）.The catalysts were investigated in detail by means of XRD,Raman,H₂-TPR,NH₃-TPD,XPS,in situ DRIFTS,and NH3-SCR reaction.The activity of the catalyst is closely related to the content of CeO₂.When the loading of CeO₂ is near the dispersion capacity(1.16 mmol Ce⁴⁺/100 m² TiO₂),the catalytic activity is better.This may be because that the dispersed CeO₂ is the active species and the catalyst has appropriate redox property,along with the larger amounts of surface Ce content and surface adsorbed oxygen species.Finally,a possible reaction mechanism via the Langmuir-Hinshelwood（L-H） mechanism is tentatively proposed to further understand the NH₃-SCR reaction.

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