| 不同SAPO分子筛负载MnOx催化剂的低温NH3-SCR性能研究 |
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| 引用本文： | 杨颖欣,马杰文,喻成龙,孙梦婷,黄碧纯,吴友明.不同SAPO分子筛负载MnOx催化剂的低温NH3-SCR性能研究[J].环境科学学报,2016,36(9):3400-3408. |
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| 作者姓名： | 杨颖欣 马杰文 喻成龙 孙梦婷 黄碧纯 吴友明 |
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| 作者单位： | 华南理工大学环境与能源学院, 广州 510006,华南理工大学环境与能源学院, 广州 510006,华南理工大学环境与能源学院, 广州 510006,华南理工大学环境与能源学院, 广州 510006,1. 华南理工大学环境与能源学院, 广州 510006;2. 华南理工大学工业聚集区污染控制与生态修复教育部重点实验室, 广州 510006,广州市环境保护科学研究院, 广州 510620 |
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| 基金项目： | 国家自然科学基金（No.51478191）；广东省省级科技计划项目（No.2014A020216003） |
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| 摘 要： | 以磷酸硅铝分子筛SAPO-5、SAPO~(-1)1和SAPO-34为载体,采用乙醇分散法制备了用于低温氨选择性还原(NH_3-SCR)NO_x的分子筛负载MnO_x催化剂.活性测试结果显示,3种分子筛催化剂均展现出优良的NH_3-SCR活性,但三者在低温区间的SCR活性存在较明显差异,其SCR活性顺序如下:MnO_x/SAPO-34MnO_x/SAPO-5MnO_x/SAPO~(-1)1.借助XRD、N2吸附-脱附、XPS、H2-TPR、NH_3-TPD、NH_3FT-IR等技术对催化剂的表面活性物种及表面酸性等进行表征分析,结果表明,MnO_x主要以无定型状态分散于载体上,负载后载体的比表面积和孔体积均有所下降.XPS和H2-TPR分析证实,不同分子筛载体上MnO_x的表面浓度与氧化态明显不同.NH_3-TPD和NH_3FT-IR分析揭示了催化剂表面均存在Bronsted酸位和Lewis酸位,其中,Lewis酸性位对低温SCR反应起着关键作用.研究表明,催化剂的催化性能会因载体不同而存在差异,高Mn4+表面浓度和丰富的Lewis酸性位对催化剂在低温区间实现优良的催化活性尤为重要.
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| 关 键 词： | 磷酸硅铝分子筛 低温选择催化还原 锰物种 催化剂载体 |
| 收稿时间： | 2015/10/29 0:00:00 |
| 修稿时间： | 2015/11/18 0:00:00 |
Low-temperature NH3-SCR activity of manganese oxides supported on different SAPO molecular sieves catalysts |
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| YANG Yingxin,MA Jiewen,YU Chenglong,SUN Mengting,HUANG Bichun and WU Youming.Low-temperature NH3-SCR activity of manganese oxides supported on different SAPO molecular sieves catalysts[J].Acta Scientiae Circumstantiae,2016,36(9):3400-3408. |
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| Authors: | YANG Yingxin MA Jiewen YU Chenglong SUN Mengting HUANG Bichun and WU Youming |
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| Institution: | College of Environment and Energy, South China University of Technology, Guangzhou 510006,College of Environment and Energy, South China University of Technology, Guangzhou 510006,College of Environment and Energy, South China University of Technology, Guangzhou 510006,College of Environment and Energy, South China University of Technology, Guangzhou 510006,1. College of Environment and Energy, South China University of Technology, Guangzhou 510006;2. Key Laboratory of the Ministry of Education for Pollution Control and Ecosystem Restoration in Industry Clusters, South China University of Technology, Guangzhou 510006 and Guangzhou Research Institute of Environmental Protection, Guangzhou 510620 |
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| Abstract: | A series of MnOx supported on SAPO-5, SAPO-11 and SAPO-34 catalysts were prepared by ethanol dispersion method and tested for selective catalytic reduction (SCR) of NOx with NH3 at low temperatures. All catalysts showed high NH3-SCR activity, but their SCR activity existed obvious difference in low temperature range. The SCR performance decreased in the order of MnOx/SAPO-34 > MnOx/SAPO-5 > MnOx/SAPO-11. The surface reactive species and surface acidity of the catalysts were characterized by XRD, N2 adsorption-desorption, XPS, H2-TPR, NH3-TPD and NH3 FT-IR. The results indicated that MnOx were mainly dispersed on the supports in amorphous state, and the specific surface area and pore volume of the supports decreased after the introduction of MnOx. XPS coupled with H2-TPR confirmed that the amounts and valence of Mn species were quite different on different support surfaces. NH3-TPD and NH3 FT-IR studies revealed the presence of both Bronsted acid sites and Lewis acid sites on these catalysts, and the Lewis acid sites played a key role in low-temperature SCR reaction. Thus, it can be concluded that the good catalytic performance of catalysts at low temperature were due to the carrier properties, rich Lewis acid sites and high surface concentration of surface Mn4+ species. |
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| Keywords: | SAPO molecular sieves low-temperature selective catalytic reduction manganese oxide catalyst support |
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