Mui Collin, Senosiain Juan P, Musgrave Charles B
Department of Chemical Engineering, Stanford University, Stanford, California 94305-5025, USA.
Langmuir. 2004 Aug 31;20(18):7604-9. doi: 10.1021/la0498410.
We use density functional theory to investigate the surface chemistry of initial oxidation and hydroxylation of the Ge(100)-2 x 1 surface by water and hydrogen peroxide. Comparison of the reaction of water on the Si(100)-2 x 1 and Ge(100)-2 x 1 surfaces shows that the kinetics of oxidation of the Ge(100)-2 x 1 surface with water is slower. Our calculations also show that oxidation products on the Ge(100)-2 x 1 surface are less thermodynamically stable than on Si. We also investigate two competing dissociation reactions of H2O2 on the Ge(100)-2 x 1 surface. We find that dissociative adsorption via cleavage of the OH bond is less exothermic than OO dissociation. Furthermore, interdimer OO dissociation has a lower activation barrier than interdimer or intradimer OH dissociation, although interdimer dissociation products are found to be less stable compared than those formed from intradimer dissociation reactions. Finally, we find that the oxidation products formed from hydrogen peroxide are more stable than those formed from water.
我们使用密度泛函理论来研究水和过氧化氢对Ge(100)-2×1表面的初始氧化和羟基化的表面化学。水在Si(100)-2×1和Ge(100)-2×1表面上反应的比较表明，水对Ge(100)-2×1表面的氧化动力学较慢。我们的计算还表明，Ge(100)-2×1表面上的氧化产物在热力学上比Si表面上的氧化产物稳定性更低。我们还研究了H2O2在Ge(100)-2×1表面上的两个相互竞争的解离反应。我们发现，通过OH键断裂的解离吸附比OO解离放热更少。此外，二聚体间的OO解离比二聚体间或二聚体内的OH解离具有更低的活化能垒，尽管发现二聚体间解离产物比二聚体内解离反应形成的产物稳定性更低。最后，我们发现由过氧化氢形成的氧化产物比由水形成的氧化产物更稳定。
