石油炼制与化工 ›› 2020, Vol. 51 ›› Issue (8): 50-55.

• 催化剂 • 上一篇    下一篇

镧改性Cu-SSZ-13分子筛用于氨选择性催化还原催化剂研究

甄铁丽1,2,李永红2,3,4   

  1. 1. 济南工程职业技术学院
    2. 天津大学化工学院绿色合成与转化教育部重点实验室
    3.精馏技术国家工程研究中心
    4.天津化学化工协同创新中心
  • 收稿日期:2020-03-30 修回日期:2020-04-27 出版日期:2020-08-12 发布日期:2020-08-27
  • 通讯作者: 甄铁丽 E-mail:zhentieli@126.com
  • 基金资助:
     

STUDY ON LANTHANUM MODIFIED Cu-SSZ-13 MOLECULAR SIEVE AS NH3-SCR CATALYST

    

  1.  
  • Received:2020-03-30 Revised:2020-04-27 Online:2020-08-12 Published:2020-08-27
  • Supported by:
     

摘要: 采用一步法制备出Cu-SSZ-13分子筛,然后用不同浓度的硝酸镧溶液对制备的分子筛进行离子改性,通过X射线衍射(XRD)、N2吸附-脱附(BET)、傅里叶变换红外光谱(FT-IR),H2程序升温还原(H2-TPR)、原位漫反射红外光谱(DRIFTS)等方法对催化剂进行表征,并评价其对氨选择性催化还原(NH3-SCR)过程的催化性能。结果表明:La0.015-Cu-SSZ-13催化剂的性能较Cu-SSZ-13有明显提高,其在 175~450 ℃范围的NO转化率达到 90%以上,具有较好的N2选择性;La改性Cu-SSZ-13的催化反应机理与Cu-SSZ-13类似,是通过表面氨物种和硝酸盐物种生成硝酸铵这一中间物种,然后硝酸铵被NO还原生成N2和H2O。

关键词: Cu-SSZ-13, La改性, NH3-SCR

Abstract: The Cu-SSZ-13 molecular sieve was prepared by one-step process and then modified by lanthanum nitrate solution with different concentration. The modified molecular sieve were used as a NH3-SCR catalyst and characterized by XRD, BET, FT-IR, TPR and DRIFTS techniques. The NH3-SCR reaction results showed that the performance of La0.015-Cu-SSZ-13 catalyst was significantly better than that of Cu-SSZ-13 catalyst, and the NO conversion rate of La0.015-Cu-SSZ-13 catalyst was more than 90% in the temperature range of 175-450 ℃ with a good N2 selectivity. The NH3-SCR mechanism of La modified Cu-SSZ-13 is similar to Cu-SSZ-13 catalyst: ammonium nitrate, an intermediate species, is generated by surface ammonia species and nitrate species, and then ammonium nitrate is reduced by NO to generate N2 and H2O.

Key words: Cu-SSZ-13, La modification, NH3-SCR

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