高等学校化学学报

高等学校化学学报 ›› 2002, Vol. 23 ›› Issue (6): 1113.

• 研究论文 • 上一篇    下一篇

氧化铝负载高分散γ-Mo2N的制备与结构表征

孟明1, 伏义路1, 刘振林1, 姜明1, 谢亚宁1, 胡天斗2   

  1. 1. 中国科学技术大学化学物理系, 合肥 230026;
    2. 中国科学院高能物理研究所, 北京 100039
  • 收稿日期:2000-12-04 出版日期:2002-06-24 发布日期:2002-06-24
  • 通讯作者: 孟　明(1967年出生),博士,副教授,主要从事催化化学研究.E-mail:mengm@ustc.edu.cn E-mail:mengm@ustc.edu.cn
  • 基金资助:

    国家自然科学基金(批准号:29873044)资助

Preparation and Structural Characterization of Highly Dispersed γ-Mo2N Supported on Alumina

MENG Ming1, FU Yi-Lu1, LIU Zhen-Lin1, JIANG Ming1, XIE Ya-Ning1, HU Tian-Dou2   

  1. 1. Department of Chemical Physics, University of Science and Technology of China, Hefei 230026,China;
    2. Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039, China
  • Received:2000-12-04 Online:2002-06-24 Published:2002-06-24

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摘要： 由NH3的程序升温还原反应(TPR)制备了不同Mo担载量的氮化态Mo/γ-Al2O3催化剂,用XRD和EXAFS方法研究了样品在氮化前后的体相结构及Mo原子局域配位结构.氮化前样品的MoK-边径向结构函数与非负载MoO3类似,样品中Mo以晶粒度较小,分散度较高的MoO3形式存在;氮化后样品的径向结构函数与非负载的γ-Mo2N基本相同,样品中Mo主要以分散度较高的γ-Mo2N形式存在.EXAFS拟合结果表明,样品的第一配位壳层(Mo—N)的配位数较非负载γ-Mo2N有明显降低,热无序和结构无序均较大,并且随担载量降低,无序度有增大的趋势.

关键词: &gamma, -Mo2N/Al2O3催化剂, 制备, 结构表征, EXAFs

Abstract: The nitrided Mo/Al2O3 catalysts were prepared by temperature programmed reaction between NH3 and MoO3/Al2O3. XRD and EXAFS methods were used for the structural characterization. The results of XRDshow that the molybdenum species in the supported samples exist as a dispersed MoO3 phase before nitriding. After nitriding, most of the molybdenum species were nitrided to form γ-Mo2N. The lower intensity of the radial structure functions of Mo Kedge and the smaller coordination number of Mo-Nshells accordingly indicate that the γ-Mo2Nin the supported samples possesses a high dispersion, the lower the loading of Mo, the higher the dispersion of γ-Mo2Non alumina. From the view of coordination distance, it is found that with the increase of dispersion of γ-Mo2N, the Mo-N distance is a little shortened, which may be resulted from the nano shortening phenomenum. The values of disorder factors show that the γ-Mo2N phase in the supported samples has big thermal and structural disorder extent, and with the increase of its dispersion, both the thermal and structural disorder factors increase.

Key words: Mo2N/Al2O3 Catalysts, Preparation, Structural Characterization, EXAFS

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