文献类型：期刊文献

英文题名：Mechanism of oxygenates formation in high temperature Fischer-Tropsch synthesis over the precipitated iron-based catalysts

作者：Mao, Wan-Yu[1]; Sun, Qi-Wen[2]; Ying, Wei-Yong[1]; Fang, Ding-Ye[1]

机构：[1] Engineering Research Center of Large Scale Reactor Engineering and Technology, State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; [2] State Key Laboratory of Coal Liquefaction and Coal Chemical Technology, Shanghai 201203, China

年份：2013

卷号：41

期号：3

起止页码：314

外文期刊名：Ranliao Huaxue Xuebao/Journal of Fuel Chemistry and Technology

收录：EI(收录号：20131616220399)

语种：英文

外文关键词：Catalysts - Iron - Molecules - Reaction intermediates

摘要：In-situ DRIFTS and chemical trapping techniques were employed to investigate the adsorbed species over the surface of precipitated iron-based catalysts and the mechanism of oxygenates formation in high temperature Fischer-Tropsch synthesis. The results showed that both linear and bridged CO molecules are present on the catalyst surface, which leads the formation of numerous oxygenated precursors. Some crucial surface intermediates are detected by the in-situ DRIFTS, such as acetate, acetyl and methoxide. The surface of precipitated iron-based catalysts is characterized by following facts: (i) alcohols are able to react with free surface hydroxyls to form alkoxy species; (ii) surface adsorbed molecules exhibit certain oxidizing ability; (iii) basic sites such as OH-and lattice oxygen may react with CH3OH or CH3CHO molecules. By chemical trapping of the CH3OH + CO and CH3I + CO + H2 reactions, it was found that acetyl is an important intermediate for oxygenates and the hydrogenation of acetyl is a crucial step for the formation of oxygenates. On the basis of these observations, the mechanism of oxygenates formation in high temperature Fischer-Tropsch synthesis over the precipitated iron-based catalysts was then proposed.