高等学校化学学报

高等学校化学学报 ›› 2001, Vol. 22 ›› Issue (12): 2052.

• 研究简报 • 上一篇    下一篇

助剂作用下金属催化剂M(M=Ru,Rh,Pd)对CO化学吸附的理论研究

刘永东, 孙仁安, 王长生   

  1. 辽宁师范大学化学系, 大连 116029
  • 收稿日期:2000-04-14 出版日期:2001-12-24 发布日期:2001-12-24
  • 通讯作者: 孙仁安(1942年出生),男,教授,从事理论与催化化学研究.
  • 基金资助:

    辽宁省教育委员会科学基金;吉林大学理论化学计算国家重点实验室资助

Theoretical Studies of the Chemisorption of CO on Metal Catalysts Under the effects of Promoters

LIU YongDong, SUN RenAn, WANG ChangSheng   

  1. Department of Chemistry, Liaoning Normal University, Dalian 116029, China
  • Received:2000-04-14 Online:2001-12-24 Published:2001-12-24

PDF (PC)

被引次数

8

摘要： 用Gaussian98程序、HF方法和LANL2DZ基组,以MCOM1n+(M=Ru,Rh,Pd;M1n+=Na+,Mg2+,K+)为模型,探讨在主族金属阳离子助剂Mn1n+作用下,过渡金属催化剂M化学吸附CO后对C—O键的影响及其机理,并进一步推测最终对CO氢化反应产物的影响.结果表明,主族金属阳离子助剂M1n+以不同方式与MCO相作用及选用不同的助剂作用时,催化剂具有不同的催化活性和选择性,且对C—O键的削弱程度不同,导致生成不同的产物.当主族金属阳离子助剂M1n+与CO中的O作用时,C—O键被削弱程度比无助剂时大,更有利于生成烃类化合物;当与过渡金属M作用时,C—O键被削弱程度减小,有利于含氧化合物的生成;当助剂与CO以侧基作用时,无助催化活性;当用不同的主族金属阳离子作助剂时,C—O键被削弱程度也不同,得电子能力强的主族金属阳离子助剂有更强的助催化作用.

关键词: CO化学吸附, 助剂作用, Abinitio计算

Abstract: The calculations have been performed for model systems MCOMn+1(M=Ru, Rh, Pd; M1n+=Na+, K+, Mg2+) by Gaussian programs at the HF/LANL2DZlevel. The influences of C—Obond and its mechanism have been studied after the COadsorbed on the main group metal cation M1n+ promoted transition metal catalysts. And the products of COhydrogenation on these catalysts have been inferred. The calculations showed that the different interaction positions of the main group metal cation promoter and the various kinds of metal cation promoters both cause the changes of catalyst activity and selectivity. When M1n+ cations affect the COthrough the Oatom of CO, the C—Obond is weakened largely and the products of COhydrogenation over these catalysts will shift to hydrocarbons. When the M1n+ cations affect the COthrough the transition metal atom, the CObond is weakened slightly, so it is beneficial to form oxygenates. And there is no activity when M1n+ cations bonded on the side of CO. It can also be concluded that the main group metal cation with stronger ability to accept the electrons may be a better promoter.

Key words: Chemisorption of CO, Promoter effect, Ab initio calculation

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