In-situ DRIFT assessment on strengthening effect of cerium over FeO_x/TiO₂ catalyst for selective catalytic reduction of NO_x with NH₃

Hossein Chitsazi¹，Ningqiang Zhang¹，Lingcong Li¹，Xiaojun Liu²，Rui Wu¹，Junda He¹，Liyun Song¹，Hong He^1,3

1. Beijing Key Laboratory for Green Catalysis and Separation and Key Laboratory of Beijing on Regional Air Pollution Control,Beijing University of Technology2. College of Chemistry,Chemical Engineering and Materials Science,Institute of Molecular and Nano Science,Shandong Normal University3. Collaborative Innovation Center of Electric Vehicle in Beijing

摘 要：Fe-based catalysts have a great potential to be used for selective catalytic reduction（SCR） of NO_x with NH3 reaction due to their low cost,nontoxicity and excellent catalytic activity.The aim of this paper is to investigate Ce doping effect on activity of NH₃-SCR over the FeO_x/TiO₂ catalyst.In-situ diffuse reflectance infrared fourier transform（DRIFT） technology was utilized to verity the adsorbed species on the surface of FeO_x/TiO₂ and FeO_x-CeO₂/TiO₂ catalysts.With respect to the obtained results,among the four catalysts studied,the FeO_x-CeO₂/TiO₂ with the FeO_x/CeO₂ ratio of 3/8 shows the best NO conversion more than 98%in the temperature range of 230—350℃,The active centers for NH₃ adsorption and activation are assigned to Lewis acid sites over the FeO_x-CeO₂/TiO₂ and monodentate nitrates can act as the key intermediate in the NH3-SCR.Moreover,both of Langmuir-Hinshelwood and Eley-Rideal mechanisms are observed over the FeO_x-CeO₂/TiO₂ catalysts in the SCR.

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