What determines the catalyst's selectivity in the ethylene epoxidation reaction
What determines the catalyst's selectivity in the ethylene epoxidation reaction
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DOI：
10.1016/j.jcat.2008.01.008
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发表时间：
2008-03-10
影响因子：
7.3
通讯作者：
Baroni, Stefano
中科院分区：
文献类型：
--
作者：
Kokalj, Anton;Gava, Paola;Baroni, Stefano
使用量子力学计算机模拟解决了乙烯环氧化反应中催化剂的选择性问题。我们发现，催化剂在氧杂金属环反应中形成环氧乙烷（EO）而不是竞争性乙醛（Ac）的选择性部分取决于催化剂对氧杂金属环的O和C原子的不同键合亲和力。 O-和C-金属键强度之间的相互作用是由于两种过渡态的不同结构造成的。基于这一发现，我们引入了一种新的指示剂，可以很好地确定多种不同材料的氧杂金属环反应中 EO 和 Ac 活化能之间的差异。 (C) 2008 Elsevier Inc. 保留所有权利。
The selectivity of a catalyst in ethylene epoxidation reaction was addressed using quantum mechanical computer simulations. We found that the catalyst's selectivity in the reaction of oxametallacycle to form ethylene epoxide (EO) rather than the competing acetaldehyde (Ac) is determined in part by the differential bonding affinity of the catalyst toward the O and C atoms of the oxametallacycle. This interplay between O- and C-metal bond strength is due to the different structures of the two transition states. Based on this finding, we introduce a new indicator that determines the difference between the EO and Ac activation energies in the oxametallacycle reaction remarkably well for a number of different materials. (C) 2008 Elsevier Inc. All rights reserved.