物理化学学报 >> 2005, Vol. 21 >> Issue (03): 278-282.doi: 10.3866/PKU.WHXB20050310

研究论文 上一篇    下一篇

Cu对Pt/Cu-Mg-Al-O催化剂上NOx储存性能的影响

康守方; 蒋政; 郝郑平   

  1. 中国科学院生态环境研究中心,北京　100085
  • 收稿日期:2004-07-23 修回日期:2004-10-11 发布日期:2005-03-15
  • 通讯作者: 郝郑平 E-mail:zpinghao@mail.rcees.ac.cn

Influence of Cu on NOx Storage Performance of Pt/Cu-Mg-Al-O Catalysts Derived from Hydrotalcites

KANG Shou-Fang; JIANG Zheng; HAO Zheng-Ping   

  1. Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing　100085
  • Received:2004-07-23 Revised:2004-10-11 Published:2005-03-15
  • Contact: HAO Zheng-Ping E-mail:zpinghao@mail.rcees.ac.cn

PDF

3616

赞

摘要： 固定二价与三价阳离子摩尔比为3∶1,采用共沉淀法合成系列Cu-Mg-Al水滑石,经500 ℃焙烧制成复合氧化物Cu-Mg-Al-O（wCuO(％)分别为0、5、10、20,简称w-CMAO, w=0、5、10、20）.通过浸渍法制备Pt/Cu-Mg-Al-O负载型复合氧化物催化剂.XRD结果表明Cu在催化剂及其前驱体中高度分散.采用等温NOx储存实验研究催化剂对NOx的储存性能, NOx-TPD法考察储存的NOx脱附情况.实验结果表明,尽管Cu取代减少了催化剂中MgO含量,但增强了催化剂的NO氧化活性,有效提高了催化剂的NOx储存性能.同时TPD结果进一步表明当CuO掺杂量在w=(10～20)％ 时,可以明显降低催化剂上生成的硝酸盐的分解温度.

关键词: 氮氧化物, 水滑石, NOx储存, 贫燃, Pt/Cu-Mg-Al-O

Abstract: A series of Cu-Mg-Al hydrotalcite compounds with M (II) :Al (III) molar ratio of 3 : 1 were prepared by co-precipitation method. Corresponding mixed oxides were obtained after calcination 500 ℃（wCuO(％)= 0, 5, 10, 20, denoted as w-CMAO, w=0, 5, 10, 20）. Pt/Cu-Mg-Al-O catalysts were prepared by impregnation with H2PtCl6 solution. XRD results showed that Cu was well dispersed in the catalysts and their precursors. NOx storage performance was investigated using NOx adsorption experiment at constant temperature, and decomposition of stored NOx was also studied by TPD method. It was shown that although MgO content was decreased due to Cu addition, the activity of NO oxidation was improved, and NOx storage performance was increased effectively. TPD results further showed that the decomposition temperature of nitrate formed on the catalysts can be reduced sharply when w=10％～20％ of CuO was added.

Key words: Nitrogen oxide, Hydrotalcite, NOx storage, Lean burn, Pt/Cu-Mg-Al-O