A quantitative determination of reaction mechanisms from density functional theory calculations: Fischer-Tropsch synthesis on flat and stepped cobalt surfaces
A quantitative determination of reaction mechanisms from density functional theory calculations: Fischer-Tropsch synthesis on flat and stepped cobalt surfaces
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DOI：
10.1016/j.jcat.2008.01.009
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发表时间：
2008-03-10
影响因子：
7.3
通讯作者：
French, Sam
中科院分区：
文献类型：
--
作者：
Cheng, Jun;Gong, Xue-Qing;French, Sam
我们利用密度泛函理论对C-1 + C-1偶联反应的机理进行了系统的研究。计算并分析了C-1 + C-1偶联反应和碳氢化反应在平面和台阶表面上的活化能。此外，吸附的C-1物种的覆盖率估计，并定量评估所有可能的C-1 + C-1耦合途径的反应速率。结果表明，在Co催化剂上FT合成反应中，CH_2 + CH_2和CH_3 + C的反应可能是C-1 + C-1偶联反应的关键步骤。研究了C-2 + C-1和C-3 + C-1偶联反应，结果表明，除了RCH + CH 2和RCH 2 + C途径外，RC + C和RC + CH偶联也可能促进C-1后的链增长。(C)2008年爱思唯尔公司All rights reserved.
We systematically investigated the mechanism of the C-1 + C-1 coupling reactions using density functional theory. The activation energies of C-1 + C-1 coupling and carbon hydrogenation reactions on both flat and stepped surfaces were calculated and analyzed. Moreover, the coverages of adsorbed C-1 species were estimated, and the reaction rates of all possible C-1 + C-1 coupling pathways were quantitatively evaluated. The results suggest that the reactions of CH2 + CH2 and CH3 + C at steps are most likely to be the key C-1 + C-1 coupling steps in FT synthesis on Co catalysts. The reactions of C-2 + C-1 and C-3 + C-1 coupling also were studied; the results demonstrate that in addition to the pathways of RCH + CH2 and RCH2 + C, the coupling of RC + C and RC + CH also may contribute to the chain growth after C-1. (C) 2008 Elsevier Inc. All rights reserved.