催化学报

催化学报 ›› 2008, Vol. 29 ›› Issue (8): 710-714.

• 研究论文 • 上一篇    下一篇

不同晶相碳化钨的肼分解性能及其CO微量吸附量热研究

孙军1,2,王兴棠1,2,王晓东1,郑明远1,王爱琴1,张涛1   

  1. 1 中国科学院大连化学物理研究所, 辽宁大连 116023; 2 中国科学院研究生院, 北京 100049
  • 收稿日期:2008-08-25 出版日期:2008-08-25 发布日期:2012-06-20

Hydrazine Decomposition and CO Adsorption Microcalorimetry on Tungsten Carbide Catalysts with Different Phases

SUN Jun1,2, WANG Xingtang1,2, WANG Xiaodong1, ZHENG Mingyuan1, WANG Aiqin1, ZHANG Tao1*   

  1. 1 Dalian Institute of Chemical Physics, The Chinese Academy of Sciences, Dalian 116023, Liaoning, China; 2 Graduate University of Chinese Academy of Sciences. Beijing 100049, China
  • Received:2008-08-25 Online:2008-08-25 Published:2012-06-20

PDF

1093

被引次数

22

摘要： 以WO3为前驱体考察了CH4/H2混合气氛下程序升温反应制备碳化钨的晶相转变过程,比较了不同晶相碳化钨催化剂的肼分解活性,并以CO为探针分子采用微量吸附量热技术研究了碳化钨晶相转变过程中催化剂的表面活性位. 结果表明,随W2C晶相的生成,催化剂对CO的吸附活化能力逐渐增强,纯相W2C表现有最好的肼分解活性. 当制备温度高于750 ℃时,样品表面形成的积炭抑制了碳化钨的催化性能. 表面洁净的WC在肼分解反应中具有优于W2C的类贵金属催化特性.

关键词: 碳化钨, 程序升温反应, 肼分解, 微量吸附量热, 积炭

Abstract: Tungsten carbides with different crystal phases were prepared by temperature-programmed reaction of WO3 in a CH4/H2 atmosphere, and the phase transition occurring during this process was described. The catalytic activity of the tungsten carbides for hydrazine decomposition was investigated, and the active sites were determined by CO adsorption microcalorimetry. The results showed that the CO adsorption became strong with the formation of a W2C crystal phase, and the W2C exhibited the best catalytic performance for N2H4 decomposition. However, when the preparation temperature was higher than 750 ℃, there was a significant amount of carbonaceous species deposited on the catalyst surface, which resulted in severe deactivation. The surface-clean WC possessed a higher intrinsic activity for N2H4 than the W2C owing to its stronger noble metallic properties.

Key words: tungsten carbide, temperature-programmed reaction, hydrazine decomposition, microcalorimetry, carbon deposition