高等学校化学学报

高等学校化学学报 ›› 2002, Vol. 23 ›› Issue (11): 2112.

• 研究论文 • 上一篇    下一篇

Ni/CeO2-Al2O3催化剂上CH4-CO2转化积炭性能的研究

杨咏来, 徐恒泳, 李文钊   

  1. 中国科学院大连化学物理研究所, 大连116023
  • 收稿日期:2001-09-12 出版日期:2002-11-24 发布日期:2002-11-24
  • 通讯作者: 徐恒泳(1963年出生),男,研究员,从事甲烷活化与催化转化研究.E-mail:xuhy@dicp.ac.cn E-mail:xuhy@dicp.ac.cn
  • 基金资助:

    国家重点基础研究发展规划项目(批准号:G1999022401)资助

Studies on Property of Carbon Deposition on Ni/CeO2-Al2O3 Catalyst for CH4-CO2 Reforming Reaction

YANG Yong-Lai, XU Heng-Yong, LI Wen-Zhao   

  1. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
  • Received:2001-09-12 Online:2002-11-24 Published:2002-11-24

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摘要： 采用脉冲微量反应技术研究了添加n型半导体氧化物CeO2对Ni基催化剂上CH4积炭/CO2消炭性能的影响,用TPR,XPS和氢吸附技术对催化剂进行了表征.结果表明,活性金属原子Ni与半导体氧化物CeO2之间存在金属-半导体相互作用(MScI),CeO2的添加提高了活性原子Ni0的d电子密度,在一定程度上抑制了CH4分子中C—Hσ电子向d轨道的迁移,降低了CH4裂解积炭活性;可加强Ni0原子d轨道向CO2空反键π轨道的电子迁移,促进CO2分子的活化,提高CO2的消炭活性,使Ni/CeO2-Al2O3催化剂具有较强的抗积炭性能.

关键词: Ni/CeO2-Al2O3催化剂, 金属-半导体相互作用, 金属-载体相互作用, CH4积炭, CO2消炭

Abstract: The influence of the addition of n-type semiconductor oxide CeO2 to Ni-based catalyst on carbon deposition from CH4 and carbon elimination by CO2 was studied by using a pulse microreaction technique. The catalysts were characterized by TPR, XPS and hydrogen chemisorption. It was found that there was an interaction between active metal Ni and semiconductor oxide CeO2. The XPS data indicated that the addition of CeO2 could increase the d-electron density of active atom Ni, which would inhibit the migration of C-H σ-electron from CH4 molecule to d-orbital of Ni atom, therefore, the carbon deposition activity of CH4 decreases. Meanwhile, the migration of d-electron from Ni atom to empty antibond π-orbital of CO2 could be strengthened due to the addition of n-type semiconductor CeO2, thereby, carbon elimination activity of CO2 increases. As a result, the Ni/CeO2-Al2O 3 catalyst has an excellent resistance to carbon deposition. In addition, the influence of the synergetic effect between SMSI and MScI on the resistance to carbon deposition of the catalysts calcined at various temperatures was investigated. It was discovered that, only in the presence of relatively weak metal-support interaction, it could exhibit the metal-semiconductor interaction(MScI).

Key words: Ni/CeO2-Al2O3 catalyst, Metal-semiconductor interaction, Metal-support interaction, Carbon deposition from CH4, Carbon elimination from CO2

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