CO Adsorption on Fe4C (100), (110), and (111) Surfaces in Fischer−Tropsch Synthesis

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• 作者：Chun-Mei Deng ; Chun-Fang Huo ; Li-Li Bao ; Gang Feng ; Yong-Wang Li ; Jianguo Wang ; Haijun Jiao
• 刊名：Journal of Physical Chemistry C
• 出版年：2008
• 出版时间：December 4, 2008
• 年：2008
• 卷：112
• 期：48
• 页码：19018-19029
• 全文大小：663K
• 年卷期：v.112,no.48(December 4, 2008)
• ISSN：1932-7455

文摘

The adsorption of CO at various coverage on the termination surfaces of the low-indexed (100), (110), and (111) surfaces of Fe₄C has been performed at the level of density functional theory. It is found that CO prefers to adsorb around Fe atoms. It is also found that there is no significant lateral interaction between the adsorbed CO at 1/4 monolayer (ML) coverage, whereas there is stronger repulsive interaction at 1 ML for (100) and (110) surfaces, and 1/2 ML for (111) surface. It is also interesting to note that the surface ketenylidene (CCO) species on (100) T_Fe/C, (110) T_Fe/C, and (111) T_C may be the precursor for CO dissociation. On all surfaces, the adsorbed CO is partially negatively charged, indicating the enhanced electron transfer from the Fe₄C surface to CO, and the more the electron transfer, the stronger the CO activation.