高等学校化学学报 ›› 2015, Vol. 36 ›› Issue (7): 1328.doi: 10.7503/cjcu20150117

• 物理化学 • 上一篇    下一篇

掺杂型烧绿石La2Sn1.7Co0.3O7-δ逆负载CeO2催化剂的甲烷催化燃烧性能

李伶聪1, 胡瑞生1(), 白雅琴1,,A;*, 李景佳1, 唐海莲2, 王军虎2, 季生福3   

  1. 1. 内蒙古大学化学化工学院, 稀土材料化学与物理重点实验室, 呼和浩特 010021
    2. 中国科学院大连化学物理研究所, 大连 116011
    3. 北京化工大学, 化工资源有效利用国家重点实验室, 北京100029
  • 收稿日期:2015-02-02 出版日期:2015-07-10 发布日期:2015-06-03
  • 通讯作者: 白雅琴 E-mail:cehrs@imu.edu.cn
  • 作者简介:联系人简介: 胡瑞生, 男, 教授, 主要从事催化材料的研究. E-mail:cehrs@imu.edu.cn;*现工作单位为呼和浩特职业学院化学系.
  • 基金资助:
    国家自然科学基金(批准号: 21263008)和北京化工大学化工资源有效利用国家重点实验室开放课题(批准号: CRE-2014-C-304)资助

Inverse CeO2/La2Sn1.7Co0.3O7-δ Catalyst for Methane Catalytic Combustion

LI Lingcong1, HU Ruisheng1,*(), BAI Yaqin1, LI Jingjia1, TANG Hailian2, WANG Junhu2, JI Shengfu3   

  1. 1. Key Laboratory of Rare Earth Materials Chemistry and Physics, College of Chemistry and Chemical Engineering,Inner Mongolia University, Hohhot 010021, China
    2. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116011, China
    3. State Key Laboratory of Beijing University of Chemical Industry Chemical Effective Utilization of Resources,Beijing University of Chemical Technology, Beijing 100029, China
  • Received:2015-02-02 Online:2015-07-10 Published:2015-06-03
  • Contact: HU Ruisheng E-mail:cehrs@imu.edu.cn
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.21263008), the State Key Laboratory Open Project of the Chemical Resources Effective Utilization of Beijing University of Chemical Technology, China(No.CRE-2014-C-304)

摘要:

用溶胶凝胶-浸渍法在900 ℃煅烧3 h后制备了烧绿石逆负载型催化剂CeO2/La2Sn1.7Co0.3O7-δ, 并用于甲烷催化燃烧反应, 显示出较好的催化燃烧活性. 催化剂还具有良好的高温热稳定性和可重复利用性能, 可使甲烷转化90%的温度(T90)降到564 ℃, 与相同条件下制备的单一烧绿石型催化剂La2Sn1.7Co0.3O7-δ和La2Sn1.7Co0.3O7-δ与CeO2机械混合的催化剂相比, T90分别降低78和135 ℃. X射线衍射结果表明, 烧绿石型逆负载催化剂具有CeO2和La2Sn1.7Co0.3O7-δ 2种物相, 在逆负载型催化剂中的CeO2比机械混合催化剂中的CeO2分散程度更好; H2程序升温还原实验也证实逆负载催化剂CeO2/La2Sn1.7Co0.3O7-δ的相应3个还原峰温度均比单一烧绿石型催化剂La2Sn1.7Co0.3O7-δ相应3个还原峰温度明显降低; 透射电子显微镜和原子力显微镜结果表明, 逆负载催化剂CeO2/La2Sn1.7Co0.3O7-δ抗烧结能力强, 颗粒分散均匀, 粒径尺寸相应较小; 穆斯堡尔谱和X射线光电子能谱结果证明逆负载催化剂CeO2/La2Sn1.7Co0.3O7-δ结构中结晶相Sn4+含量较高, 表面晶格氧数量较多, 这是烧绿石逆负载型催化剂具有良好甲烷催化燃烧性质的主要原因.

关键词: 逆负载催化剂, 烧绿石, 二氧化铈, 甲烷催化燃烧

Abstract:

The inverse CeO2/La2Sn1.7Co0.3O7-δ catalyst was prepared by sol-gel and impregnation method calcined at 900 ℃ and investigated in the methane catalytic combustion. The catalytic activity evaluated for methane combustion showed that the methane conversion temperature of T90 was 564 ℃, compared with the pure La2Sn1.7Co0.3O7-δ prepared in the same condition and mechanical mixing of La2Sn1.7Co0.3O7-δ and CeO2, T90 decreased by 78 ℃ and 135 ℃, respectively, and the inverse CeO2/La2Sn1.7Co0.3O7-δ catalyst not only had the excellent methane combustion activity, but also had the well thermal stability and reusable performance. The excellent performance of the inverse CeO2/La2Sn1.7Co0.3O7-δ catalyst was represented by the characterizations of XRD, TEM, AFM, TPR, BET, XPS and Mössbauer spectra. XRD characterization showed that the inverse CeO2/La2Sn1.7Co0.3O7-δ catalyst not only had the La2Sn1.7Co0.3O7-δ structure, but also had the CeO2 phase, and the CeO2 had been well disperse on the La2Sn1.7Co0.3O7-δ composite oxide; TPR indicated that the CeO2/La2Sn1.7Co0.3O7-δ had lower reduction temperature compared to La2Sn1.7Co0.3O7-δ, XPS and Mössbauer spectra indicated that the Sn4+ is the main valence state in the inverse catalyst, and the lattice oxygen play an important role in catalytic activity; TEM and BET tests showed that the CeO2/La2Sn1.7Co0.3O7-δ particles had better dispersed and larger surface area than La2Sn1.7Co0.3O7-δ. All above explained the reasons of the CeO2/La2Sn1.7Co0.3O7-δ catalyst had excellent catalytic activity toward methane combustion.

Key words: Inverse catalyst, Pyrochlore, Ceric oxide, Methane catalytic combustion

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