洁净煤技术

2020, v.26;No.129(05) 56-63

[打印本页] [关闭]
本期目录(Current Issue) | 过刊浏览(Past Issue) | 高级检索(Advanced Search)

煅烧气氛对柠檬酸溶胶凝胶铁氧化物催化剂低温SCR脱硝性能的影响
Effect of calcination atmosphere on low-temperature denitrification of citric acid sol-gel iron oxide catalyst

宋唯一;朱宝忠;孙运兰;谢超越;
SONG Weiyi;ZHU Baozhong;SUN Yunlan;XIE Chaoyue;School of Petroleum Engineering,Changzhou University;

摘要(Abstract):

煅烧气氛对催化剂的活性有重要影响,为了优化柠檬酸溶胶凝胶铁氧化物(Fe_2O_3/LA)低温烟气脱硝催化剂的制备工艺,明确煅烧气氛对Fe_2O_3/LA催化剂低温脱硝性能的影响规律,通过柠檬酸(LA)溶胶-凝胶法制备了Fe_2O_3/LA-Air和Fe_2O_3/LA-Ar低温脱硝催化剂,并采用N_2吸附-脱附(BET)、X射线粉末衍射(XRD)、氢气升温还原(H_2-TPR)、氨气升温脱附(NH_3-TPD)、X光电子能谱(XPS)等对催化剂进行了表征。结果表明:Fe_2O_3/LA-Air催化剂与Fe_2O_3/LA-Ar催化剂相比高温脱硝活性较差,但具有更好的低温脱硝活性,尤其在120~200℃,其脱硝效率达80%~100%;且其N_2吸附-脱附曲线呈H3型滞后环Ⅱ型等温线,具有更大的孔径;在270℃具有典型的中低温H_2还原峰,中低温还原能力强;2种气氛下煅烧的Fe_2O_3/LA催化剂主要活性成分皆为γ-Fe_2O_3,且Fe_2O_3/LA-Air催化剂中Fe~(3+)含量比Fe_2O_3/LA-Ar催化剂Fe~(3+)含量高3.24%,表面吸附氧O_β含量高48.24%;Fe_2O_3/LA-Ar催化剂中温和高温氨脱附峰均向高温方向移动,其中高温氨脱附峰面积比Fe_2O_3/LA-Air催化剂脱附峰面积大,Lewis酸位点数量多,但Fe_2O_3/LA-Air催化剂Br9nsted酸位点比Fe_2O_3/LA-Ar催化剂多,这些因素使得空气气氛下煅烧的Fe_2O_3/LA催化剂低温段的脱硝活性优于氩气气氛下煅烧的Fe_2O_3/LA催化剂的脱硝活性。
Calcination atmosphere has an important influence on the activity of catalyst. To optimize the preparation process of citric acid sol-gel iron oxide( Fe_2O_3/LA) low-temperature denitrification catalyst and clarify the effects of calcination atmosphere on the low-temperature denitrification performance of Fe_2O_3/LA catalyst,the Fe_2O_3/LA-Air and Fe_2O_3/LA-Ar catalysts were prepared by a citric acid( LA) sol-gel method and the catalysts were characterized by N_2 adsorption desorption( BET),X-ray powder diffraction( XRD),H_2 reduction by heating( H_2-TPR),NH_3-temperature desorption( NH_3-TPD) and X-ray photoelectron spectroscopy( XPS). The results show that Fe_2O_3/LA-Air catalyst has poorer denitrification activity at high temperature compared with Fe_2O_3/LA-Ar catalyst,while it has better denitrification performance at low temperature,especially at 120-240 oC,of which the NOxconversions can reach 80-100%. And its nitrogen adsorption-desorption curve is H_3 type hysteresis loop Ⅱ type isotherm with larger pores. The Fe_2O_3/LA-Air catalyst has a typical H_2 reduction peak of medium and low temperatures at 270 oC,which has strong reduction capacity. The main active ingredients of the catalysts calcined at two atmospheres are γ-Fe_2O_3. The contents of Fe~(3+) and surface adsorption oxygen Oβin Fe_2O_3/LA-Air catalyst are 3.24% and 48.24% higher than those of the Fe_2O_3/LA-Ar,repectively. For the Fe_2O_3/LA-Ar catalyst,its peaks of ammonia desorption at moderate and high temperatures all move towards high temperature,and the peak area of ammonia desorption at high temperature is larger than that of Fe_2O_3/LA-Air catalyst,so there are more Lewis acid sites. However,the Bronsted acid sites of Fe_2O_3/LA-Air catalyst are more than those of Fe_2O_3/LA-Ar catalyst. These factors are responsible for that the denitrification activity of Fe_2O_3/LA catalyst calcined in air atmosphere at low temperature is better than that of Fe_2O_3/LA catalyst calcined in argon atmosphere.

关键词(KeyWords): 煅烧气氛;脱硝性能;酸位点;Fe_2O_3/LA催化剂;低温
calcination atmosphere;denitrification performance;acid site;Fe_2O_3/citric acid catalyst;low temperature

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金资助项目(51676001);; 江苏省六大人才高峰项目(JNHB-097)

作者(Author): 宋唯一;朱宝忠;孙运兰;谢超越;
SONG Weiyi;ZHU Baozhong;SUN Yunlan;XIE Chaoyue;School of Petroleum Engineering,Changzhou University;

Email:

DOI: 10.13226/j.issn.1006-6772.IF20080602

参考文献(References):

文章评论(Comment):

序号(No.) 时间(Time) 反馈人(User) 邮箱(Email) 标题(Title) 内容(Content)
反馈人(User) 邮箱地址(Email)
反馈标题(Title)
反馈内容(Content)
扩展功能
本文信息
服务与反馈
本文关键词相关文章
本文作者相关文章
中国知网
分享