高等学校化学学报

高等学校化学学报 ›› 2004, Vol. 25 ›› Issue (6): 1090.

• 研究论文 • 上一篇    下一篇

预处理条件对Pt/Al2O3催化还原NO的活性影响

王静, 傅立新, 李俊华   

  1. 清华大学环境科学与工程系, 北京 100084
  • 收稿日期:2003-07-18 出版日期:2004-06-24 发布日期:2004-06-24
  • 通讯作者: 傅立新(1966年出生),男,博士,教授,从事大气环境机动车污染控制的研究.E-mail:fuchen@tsinghua.edu.cn E-mail:fuchen@tsinghua.edu.cn
  • 基金资助:

    国家“八六三”计划(批准号:2001AA643030)资助

Effect of Pretreatment Conditions on the Activity of Catalytic Reduction of NO over Pt/Al2O3 Catalyst

WANG Jing, FU Li-Xin, LI Jun-Hua   

  1. Department of Environment Science and Engineering, Tsinghua University, Beijing 100084, China
  • Received:2003-07-18 Online:2004-06-24 Published:2004-06-24

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摘要： 用溶胶-凝胶法制备Al2O3载体,浸渍法制备质量分数为0.5%的Pt/Al2O3催化剂.研究焙烧气氛和温度对选择性催化还原NO反应活性和Pt价态的影响.结果表明,H2焙烧的活性温度区间最宽,随着焙烧温度的升高,温度区间变化很小,523K下O2焙烧的催化剂活性最好,且活性区间向高温方向移动.活性现象用程序升温脱附实验(NO-TPD,NO-O2-TPD)进行了解释.XPS研究表明,523K下O2用焙烧Pt的主要价态是Pt2+,而523K下H2和N2焙烧Pt的主要价态为Pt0.

关键词: 预处理, Pt/Al2O3, 催化还原NO

Abstract: Pt/Al2O3 catalysts were prepared by impregnation method in which Pt loading was fixed at mass fraction 0.5%,and the Al2O3 carrier was prepared by sol-gel method. The activity for selective catalytic reduction of nitric oxide by propene in the presence of oxygen over Pt/Al2O3 catalyst was investigated and the bonding state of Pt in the samples pre-treated under different conditions was studied. It has been found that the activity window of the catalyst calcined in H2 is the widest,and it changed little when the calcined temperature increased;the catalyst activity of the catalyst pretreated in O2 at 523 K is the highest,the activity window shifted to a higher temperature when the calcined temperature increased. The reason of the activity difference is explained by the temperature programmed desorption. According to XPS measurements,the main bonding state of platinum supported on Al2O3 is Pt2+ calcined in O2 at 523 K,and Pt0 calcined in N2 and H2 at 523 K,respectively.

Key words: Pretreatment, Pt/Al2O3, Catalytic reduction of NO

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