Geometric stability and reaction activity of Pt clusters adsorbed graphene substrates for catalytic CO oxidation.
Geometric stability and reaction activity of Pt clusters adsorbed graphene substrates for catalytic CO oxidation.
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DOI：
10.1039/c5cp00052a
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发表时间：
2015-04
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影响因子：
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通讯作者：
Yanan Tang;Zhansheng Lu;Weiguang Chen;Wei Li;X. Dai
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文献类型：
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作者：
Yanan Tang;Zhansheng Lu;Weiguang Chen;Wei Li;X. Dai
采用第一性原理方法研究了锚定在石墨烯衬底上的四面体Pt 4团簇的几何稳定性、电子结构和催化性能。结果表明，吸附在石墨烯基底上的Pt 4小团簇容易通过较小的能垒发生结构异构体间的相互转化，而吸附在缺陷石墨烯和氧掺杂石墨烯（O-graphene）上的Pt 4团簇发生结构异构体间的相互转化具有较大的能垒.与其他石墨烯衬底相比，负载在O-石墨烯衬底上的Pt 4团簇（Pt 4/O-graphene）具有最小的几何畸变，并且Pt 4团簇的高度对称性可以提高反应气体的灵敏度。此外，CO在Pt 4/O-graphene上氧化的顺序反应进行了研究，以进行比较。与CO和O2分子的共吸附反应相比，作为起始步骤的O2的解离吸附具有小的能垒（0.07 eV），并且随后通过具有0.42 eV的能垒的Eley-Rideal反应（CO + Oads → CO2）。研究结果为石墨烯基催化剂阳极材料的制备提供了有价值的指导，并探索了原子级催化剂上CO氧化反应的微观机理。
The geometric stabilities, electronic structures and catalytic properties of tetrahedral Pt4 clusters anchored on graphene substrates are investigated using the first-principles methods. It is found that the small Pt4 clusters adsorbed on pristine graphene substrates easily interconvert between structural isomers by the small energy barriers, while the structural interconversion of Pt4 clusters on the defective graphene and oxygen-doped graphene (O-graphene) have the large energy barriers. Compared to other graphene substrates, the Pt4 clusters supported on the O-graphene substrate (Pt4/O-graphene) have the least geometrical distortion and the high symmetry of the Pt4 cluster can enhance the sensitivity of reactive gases. Moreover, the sequential reactions of CO oxidation on Pt4/O-graphene are investigated for comparison. Compared with the coadsorption reaction of CO and O2 molecules, the dissociative adsorption of O2 as a starting step has a small energy barrier (0.07 eV) and is followed through the Eley-Rideal reaction with an energy barrier of 0.42 eV (CO + Oads → CO2). The results provide valuable guidance for fabricating graphene-based catalysts as anode materials, and explore the microscopic mechanism of the CO oxidation reaction on atomic-scale catalysts.