| Sm掺杂对Fe2O3催化剂NH3-SCR反应活性及抗水抗硫性作用 |
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| 引用本文： | 孙传智,陈葳,贾轩轩,刘安鼐,高飞,冯帅,董林.Sm掺杂对Fe2O3催化剂NH3-SCR反应活性及抗水抗硫性作用[J].催化学报,2021,42(3):417-430,中插19-中插24. |
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| 作者姓名： | 孙传智 陈葳 贾轩轩 刘安鼐 高飞 冯帅 董林 |
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| 作者单位： | 山东师范大学化学化工与材料科学学院, 化学成像功能探针协同创新中心, 山东省精细化学品清洁合成重点实验室,山东济南250014;南京大学环境学院, 江苏省机动车尾气污染控制重点实验室, 现代分析中心, 江苏南京210093;山东师范大学化学化工与材料科学学院, 化学成像功能探针协同创新中心, 山东省精细化学品清洁合成重点实验室,山东济南250014;南京大学环境学院, 江苏省机动车尾气污染控制重点实验室, 现代分析中心, 江苏南京210093;泰山学院化学化工学院, 山东泰安271021 |
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| 基金项目： | 国家自然科学基金;and Shandong Provincial Natural Science Foundation ;This work was supported by the National Natural Science Foundation of China ;山东省自然科学基金 |
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| 摘 要： | 氮氧化物(NOx)是主要的环境污染物之一,会造成酸雨、光化学烟雾和温室效应等环境问题.氨选择性催化还原(NH3-SCR)技术是目前控制NOx排放的最有效技术.其中,Fe2O3催化剂因其良好的抗硫性和低廉的成本而受到广泛关注,有望用作NOx消除催化剂,但是它的低温还原性差、脱硝效率低等缺点限制了其应用.近期研究表明,钐掺杂金属氧化物可以调节其表面酸碱性及氧化还原性,可有效提高氧化物催化剂的脱硝效率和抗水抗硫性能.因此,将铁、钐二者优势结合,为合成一种低温、高效、环境友好型脱硝催化剂提供了可能.本文通过柠檬酸辅助的溶胶凝胶法合成了一系列钐均匀掺杂入Fe2O3纳米颗粒的复合氧化物脱硝催化剂,采用X射线光电子能谱(XPS),氢气程序升温还原(H2-TPR),氨气程序升温脱附(NH3-TPD)以及原位漫反射红外光谱(in situ DRIFTS)等方法研究了钐的掺杂对铁基催化剂脱硝效率和抗水抗硫性的影响,旨在揭示催化剂表面物理化学性质和催化活性之间的关系.通过活性测试发现,钐的掺杂可以使Fe0.94Sm0.06Ox催化剂在175?325℃时实现>95%的脱硝效率和>93%的N2选择性.动力学测试研究表明,当基于催化剂的比表面积计算时,Fe0.94Sm0.06Ox催化剂的脱硝效率是纯Fe2O3催化剂的11倍;基于质量计算时则为37倍.此外,250℃时抗水抗硫测试结果显示,Fe0.94Sm0.06Ox催化剂可以在通入200×10-6SO2+5 vol%H2O,空速为90000 h-1时脱硝效率保持83%达168小时,并且在切断H2O和SO2后,该催化剂的脱硝效率可以很快完全恢复.XPS和H2-TPR结果表明,钐的掺杂使Fe0.94Sm0.06Ox催化剂的表面产生了大量的表面吸附氧,从而促进了NO的氧化以及快速NH3-SCR反应的进行.NH3-TPD与原位DRIFTS结果表明,钐的掺杂增强了催化剂的表面酸性,有效地提高了NH3的吸附和活化能力,进而提高了催化剂的脱硝效率.另外,钐的掺杂还可以促使NH4HSO4在Fe0.94Sm0.06Ox催化剂表面较低温度下的分解,从而使催化剂具有很好的抗水抗硫性能.
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| 关 键 词： | 氨选择性催化还原 NOx消除 钐掺杂Fe2O3催化剂 抗水抗硫性能 168小时测试 |
Comprehensive understanding of the superior performance of Sm-modified Fe2O3 catalysts with regard to NO conversion and H2O/SO2 resistance in the NH3-SCR reaction |
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| Chuanzhi Sun,Wei Chen,Xuanxuan Jia,Annai Liu,Fei Gao,Shuai Feng,Lin Dong.Comprehensive understanding of the superior performance of Sm-modified Fe2O3 catalysts with regard to NO conversion and H2O/SO2 resistance in the NH3-SCR reaction[J].Chinese Journal of Catalysis,2021,42(3):417-430,中插19-中插24. |
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| Authors: | Chuanzhi Sun Wei Chen Xuanxuan Jia Annai Liu Fei Gao Shuai Feng Lin Dong |
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| Institution: | (Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong,Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals,College of Chemistry,Chemical Engineering and Materials Science,Shandong Normal University,Jinan 250014,Shandong,China;Jiangsu Key Laboratory of Vehicle Emissions Control,Center of Modern Analysis,School of the Environment,Nanjing University,Nanjing 210093,Jiangsu,China;College of Chemistry and Chemical Engineering,Taishan University,Taian 271021,Shandong,China) |
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| Abstract: | Sm-doped Fe2O3 catalysts, with a homogeneous distribution of Sm in Fe2O3 nanoparticles, were synthesized using a citric acid-assisted sol-gel method. Kinetic studies show that the reaction rate for NOx reduction using the optimal catalyst (0.06 mol％doping of Sm in Fe2O3) was nearly 11 times higher than that for pure Fe2O3, when calculated based on specific surface area. Furthermore, the Fe0.94Sm0.06Ox catalyst maintains> 83％NOx conversion for 168 h at a high space velocity in the presence of SO2 and H2O at 250 ℃. A substantial amount of surface-adsorbed oxygen was generated on the surface of Fe0.94Sm0.06Ox, which promoted NO oxidation and the subsequent fast reaction between NOx and NH3. The adsorption and activation of NH3 was also enhanced by Sm doping. In addition, Sm doping facilitated the decomposition of NH4HSO4 on the surface of Fe0.94Sm0.06Ox, re-sulting in its high activity and stability in the presence of SO2+H2O. |
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| Keywords: | NH3-SCR NOx conversion Sm-doped Fe2O3 SO2 and H2O tolerance 168 h test |
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