DFT study into the reaction mechanism of CO methanation over pure MoS2
DFT study into the reaction mechanism of CO methanation over pure MoS2
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纯MoS2上CO甲烷化反应机理的DFT研究
DOI：
10.1002/qua.25643
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发表时间：
2018
影响因子：
2.2
通讯作者：
Xinbin Ma
中科院分区：
文献类型：
--
作者：
Zhenhua Li;Kan Zhang;Weihan Wang;Baowei Wang;Xinbin Ma
Mo基催化剂通常用于CO的直接甲烷化;然而，由于在表征MoS 2的纳米级活性结构方面的限制，尚未提出综合机制。因此，我们报告了我们的调查CO甲烷化纯MoS 2通过密度泛函理论模拟的机制，考虑到只有MoS 2边缘网站表现出催化活性。模拟结果表明，MoS 2表面存在（010）和（110）面。这两个表面都是通过暴露于H2/H2S时表面硫原子的重新分布而重构的，并且在硫覆盖重新分布之后，产生用于CO加氢的S空位。讨论了两种表面上的反应机理，S边比（010）表面上的Mo边更适合CO甲烷化。速率控制步骤在表面之间不同，并且对应于初始活化反应，其在（110）表面上更容易实现。
Mo‐based catalysts are commonly used in the direct methanation of CO; however, no integrated mechanism has been proposed due to limits in characterizing the nano‐sized active structures of MoS2. Thus, we report our investigation into the mechanism of CO methanation over pure MoS2through density functional theory simulations, considering that only MoS2edge sites exhibit catalytic activity. Simulations revealed the presence of (010) and (110) surfaces on the MoS2edges. Both surfaces are reconstructed by the redistribution of surface sulfur atoms upon exposure to H2/H2S, and after sulfur coverage redistribution, S vacancies are generated for CO hydrogenation. The reaction mechanisms on both surfaces are discussed, with the S‐edge being better suited to CO methanation than Mo‐edge on the (010) surface. The rate‐controlling step differs between surfaces, and corresponds to the initial activation reaction, which was achieved more easily on the (110) surface.