期刊
SURFACE SCIENCE
卷 602, 期 3, 页码 733-743出版社
ELSEVIER
DOI: 10.1016/j.susc.2007.12.008
关键词
nickel; carbon monoxide; sulfur; nickel carbonyl; CO dissociation; methanation; Fischer-Tropsch; surface defects
The dissociation of CO was investigated on a stepped Ni(141313) crystal. The experiments show that the monoatomic steps completely dominate the dissociation of CO on the nickel surface. The activation energy for dissociation of CO along the steps is measured at 500 K to be 150 kJ/mol in the pressure range 1-7 X 10(-6) mbar CO. Poisoning the steps by preadsorbing 0.05 ML sulfur, the dissociation rate was reduced by more than a factor of 50 clearly providing evidence for the step activity. Furthermore, by deliberately adding remote amounts of nickel carbonyl (0.25%) to the CO gas, it is shown that the dissociation probability of CO is increased by a factor of 60 compared to when using a purified CO gas. This clearly demonstrates the importance of avoiding nickel carbonyl when CO dissociation is studied. CO dissociation is important because it is believed to be the rate limiting step in methanation and in the Fischer-Tropsch synthesis. (C) 2007 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据