Hydrogen adsorption energies on bimetallic systems at the solid-vacuum overlayer and the solid-liquid interface
Hydrogen adsorption energies on bimetallic systems at the solid-vacuum overlayer and the solid-liquid interface
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DOI：
10.1016/j.susc.2004.02.040
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发表时间：
2005-12-15
期刊：
影响因子：
1.9
通讯作者：
Gross, A
中科院分区：
文献类型：
--
作者：
Roudgar, A;Gross, A
用周期密度泛函理论在广义梯度近似下计算了氢原子在叠层体系上的吸附能。在赝晶Pd/Cu（111）表面上，由于基底相互作用和Pd覆盖层的晶格压缩，氢结合能减小。另一方面，对于假晶Cu/Pd（111），强的Cu-Pd相互作用导致较大的结合能。因此，Pd/Cu（111）和Cu/Pd（111）都表现出介于纯Cu（111）和纯Pd（111）之间的中间行为。此外，我们还测定了水覆盖层存在下氢原子在Pd/Au（111）上的吸附。最稳定的H2O双层的氢吸附能的变化小于60毫电子伏相比，清洁的表面。这表明，在固体-真空界面的理论吸附研究也可能是相关的固液界面。(c)2005 Elsevier B. V.保留所有权利。
Atomic hydrogen adsorption energies on bimetallic overlayer systems have been determined by periodic density functional theory calculations within the generalized gradient approximation. On the pseudomorphic Pd/Cu(111) surface, both the substrate interaction and the lattice compression of the Pd overlayer lead to smaller hydrogen binding energies. For pseudomorphic Cu/Pd(111), on the other hand, the strong Cu-Pd interaction results in larger binding energies. Hence, both Pd/Cu(111) and Cu/Pd(111) exhibit an intermediate behavior between pure Cu(1 11) and pure Pd(111). In addition, we have determined the atomic hydrogen adsorption on Pd/Au(111) in the presence of a water overlayer. The hydrogen adsorption energies are changed by less than 60 meV by the most stable H2O bilayer compared to the clean surface. This indicates that theoretical adsorption studies at the solid-vacuum interface might also be relevant for the solid-liquid interface. (c) 2005 Elsevier B.V. All rights reserved.