A DFT STUDY ON THE REACTION MECHANISM OF SrO + CH4
A DFT STUDY ON THE REACTION MECHANISM OF SrO + CH4
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DOI：
10.1142/s0219633608003708
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发表时间：
2008-04
影响因子：
2.4
通讯作者：
Song Qin;Huaqing Yang;Jian Xu;D. Tang;Changwei Hu
中科院分区：
文献类型：
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作者：
Song Qin;Huaqing Yang;Jian Xu;D. Tang;Changwei Hu
在B3LYP/SDD，Aug-cc-pVQZ//B3LYP/SDD，6-311+G(2df，2p)理论水平下，在单重态势能面上研究了SRO+CH4的反应机理。首先，反应物给出了两个分子-分子络合物：(I)C-O键共线的C-H方法，形成具有C3v对称性的SrOCH4分子络合物；(Ii)C-H键的侧向-侧向方法，形成具有C1对称性的OSrCH4分子络合物。从SrOCH4出发，通过直接从CH4部分抽出氢原子而形成SrOH+CH3自由基。从OSrCH4出发，SRO的气相甲烷转化为甲醇是通过SRO插入CH4的C-H键生成羟基和甲氧基中间体HOSrCH3和HSrOCH3，且通过羟基中间体(HOSrCH3)的反应途径比通过甲氧基中间体(HSrOCH3)的反应途径在能量上更有利。这些形成(SrOH+CH3)和(Sr+CH3OH)的通道有望相互竞争。
The reaction mechanism of SrO + CH4 has been investigated on a singlet spin state potential energy surface at the B3LYP/SDD, AUG-cc-pVQZ//B3LYP/SDD, 6-311+G(2df, 2p) levels of theory. Initially, the reactants give two molecule–molecule complexes: (i) a collinear C–H approach to O-end of the Sr–O bond forming SrOCH4 molecular complex with C3v symmetry, and (ii) a side-on to side-on approach of C–H bond to Sr–O forming OSrCH4 molecular complex with C1 symmetry. From SrOCH4, the SrOH + CH3 radicals are formed by the direct abstraction of a hydrogen atom from CH4 moiety. From OSrCH4, the gas-phase methane to methanol conversion by SrO is suggested to involve the SrO insertion into a C–H bond of CH4 to produce the hydroxy and methoxy intermediates, HOSrCH3 and HSrOCH3, and the reaction pathway via the hydroxy intermediate (HOSrCH3) is energetically more favorable than the other one via the methoxy intermediate (HSrOCH3). These channels to form (SrOH + CH3) and (Sr + CH3OH) are expected to compete with each oth...