Fast x-ray spectroscopy study of ethene on clean and SO4 precovered Pt{111}
Fast x-ray spectroscopy study of ethene on clean and SO4 precovered Pt{111}
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洁净和 SO4 预覆盖的 Pt 上乙烯的快速 X 射线光谱研究{111}
DOI：
10.1116/1.1559923
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
K. Wilson
中科院分区：
文献类型：
--
作者：
A. Lee;K. Wilson
用快X射线能谱研究了乙烯在铂{111}单晶表面的吸附和分解。在100K时，乙烯表现为前体介导的吸附动力学，采用单一环境，饱和C2H4覆盖率为0.25ML，结合能为283.2 eV。在240K以上通过脱氢生成乙叉进行热分解，其活化势垒为57±3kJ −1，指前因子ν=1×10 10±0.5 S−1.被预吸附的SO4位封闭减少了乙烯的饱和覆盖度，但在283.9 eV附近生成了一个新的活性较低的π键合的乙烯物种，在350K分解为乙叉.
The adsorption and decomposition of ethylene over a Pt{111} single crystalsurface has been investigated by fast x-ray spectroscopy. At 100 K ethene displays precursor-mediated adsorption kinetics, adopting a single environment with a saturation C2H4 coverage of 0.25 ML and binding energy of 283.2 eV. Thermal decomposition proceeds above 240 K via dehydrogenation to ethylidyne with an activation barrier of 57±3 kJ mol−1 and preexponential factor ν=1×1010±0.5 s−1. Site-blocking by preadsorbed SO4 reduces the saturation ethene coverage but induces a new, less reactive π-bonded ethene species centered around 283.9 eV, which in turn decomposes to ethylidyne at 350 K.