BEP relations for N2 dissociation over stepped transition metal and alloy surfaces.
BEP relations for N2 dissociation over stepped transition metal and alloy surfaces.
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DOI：
10.1039/b720021h
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发表时间：
2008-08
期刊：
影响因子：
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通讯作者：
Ture R. Munter;T. Bligaard;C. Christensen;J. Nørskov
中科院分区：
文献类型：
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作者：
Ture R. Munter;T. Bligaard;C. Christensen;J. Nørskov
我们提出了密度泛函理论（DFT）计算在台阶面心立方（211）表面板上的N2解离。利用相同的晶体结构、相同的氮原子吸附位点和相同的N2过渡态键长，在一定范围的纯金属表面上，获得了过渡态势能与解离化学吸附能之间的完美线性Brønsted-Evans-Polanyi （BEP）关系。完美的BEP关系（化学吸附能超过12 eV）表明，表面反应的BEP关系表现为一般的电子结构效应，而通常在BEP线周围观察到的散射是几何效应造成的。BEP关系对表面合金和块状合金都是有效的。然而，这种散射比纯元素的散射要大。这可以理解为一个更大的几何方差。为了分析DFT计算的准确性，对阶梯式六角形密实和面心立方Ru板上的几种吸附进行了详细的收敛研究。
We present density functional theory (DFT) calculations for N2 dissociation on stepped face-centred cubic (211) surface slabs. By using the same crystal structure, the same adsorption site for atomic nitrogen, and the same transition-state bond length of N2 over a range of pure metal surfaces, a perfectly linear Brønsted-Evans-Polanyi (BEP) relation between the transition-state potential energy and the dissociative chemisorption energy is obtained. The perfect BEP relation, which extends over 12 eV in chemisorption energy, suggests that the manifestation of BEP relations for surface reactions is a general electronic structure effect, and that geometric effects are responsible for the scatter which is normally observed around the BEP line. The BEP relation is also shown to be valid for both surface and bulk alloys. The scatter is, however, larger than for the pure elements. This can be understood as a larger geometrical variance. To analyze the accuracy of the DFT calculations a detailed convergence study is performed for several adsorbates on stepped hexagonal close-packed and face-centred cubic Ru slabs.