FeTiOx has been recognized as an environmental-friendly and cost-effective catalyst for selective catalytic reduction(SCR)of NOx with NH3.Aimed at further improving the low-temperature DeNOx efficiency of FeTiOx catalyst,a simple strategy of CeO2 doping was proposed.The low-temperature(＜250℃)NH3-SCR activity of FeTiOx catalyst could be dramatically enhanced by CeO2 doping,and the optimal composition of the catalyst was confirmed as FeCe0.2TiOx,which performed a NOx conversion of 90％at ca.200℃.According to X-ray diffraction(XRD),Raman spectra and X-ray absorption fine structure spectroscopy(XAFS)analysis,FeCe0.2TiOx showed low crystallinity,with Fe and Ce species well mixed with each other.Based on the fitting results of extended X-ray absorption fine structure(EXAFS),a unique Ce-O-Fe structure was formed in FeCe0.2TiOx catalyst.The well improved specific surface area and the newly formed Ce-O-Fe structure dramatically contributed to the improvement of the redox property of FeCe0.2TiOx catalyst,which was well confirmed by H2-temperature-programmed reduction(H2-TPR)and in situ XAFS experiments.Such enhanced redox capability could benefit the activation of NO and NH3 at low temperatures for NOx removal.The detailed reaction mechanism study further suggested that the facile oxidative dehydrogenation of NH3 to highly reactive-NH2 played a key role in enhancing the low-temperature NH3-SCR performance of FeCe0.2TiO,catalyst.

Department of Civil,Environmental,and Construction Engineering,Catalysis Cluster for Renewable Energy and Chemical Transformations(REACT),NanoScience Technology Center(NSTC),University of Central Florida,Orlando,FL32816,USA;Key Laboratory of Mesoscopic Chemistry of MOE,School of Chemistry and Chemical Engineering,Jiangsu Key Laboratory of Vehicle Emissions Control,School of Environment,Center of Modern Analysis,Nanjing University,Nanjing 210023,China;State Key Joint Laboratory of Environment Simulation and Pollution Control,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;Key Laboratory of Urban Pollutant Conversion,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China;Institute of Engineering Technology,Sinopec Catalyst Co.Ltd.,Sinopec Group,Beijing 101111,China

[1]Wei Tan;Shaohua Xie;Wenpo Shan;Zhihua Lian;Lijuan Xie;Annai Liu;Fei Gao;Lin Dong;Hong He;Fudong Liu-.CeO2 doping boosted low-temperature NH3-SCR activity of FeTiOx catalyst:A microstructure analysis and reaction mechanistic study)[J].环境科学与工程前沿,2022(05):69-81

FeTiOx,DeNOx,FeCe0,2TiOx,2TiO

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