Han Jeong Woo, Kitchin John R, Sholl David S
School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332-0100, USA.
J Chem Phys. 2009 Mar 28;130(12):124710. doi: 10.1063/1.3096964.
Highly stepped metal surfaces can define intrinsically chiral structures and these chiral surfaces can potentially be used to separate chiral molecules. The decoration of steps on these surfaces with additional metal atoms is one potential avenue for improving the enantiospecificity of these surfaces. For a successful step decoration, the additional metal atoms should ideally remain at the kinked step sites on the surface. We performed density functional theory (DFT) calculations to identify pairs of metal adatoms and metal surfaces where this kind of step decoration could be thermodynamically stable. These calculations have identified multiple stable examples of step decoration. Using our DFT results, we developed a model to predict surface segregation on a wide range of stepped metal surfaces. With this model, we have estimated the stability of step decoration without further DFT calculations for surface segregation for all combinations of the 3d, 4d, and 5d metals.
高度阶梯状的金属表面可以定义固有的手性结构，并且这些手性表面有可能用于分离手性分子。用额外的金属原子修饰这些表面上的台阶是提高这些表面对映体特异性的一个潜在途径。对于成功的台阶修饰，额外的金属原子理想情况下应保留在表面的扭折台阶位点上。我们进行了密度泛函理论（DFT）计算，以确定这种台阶修饰在热力学上可能稳定的金属吸附原子与金属表面的配对。这些计算确定了多个台阶修饰的稳定实例。利用我们的DFT结果，我们开发了一个模型来预测广泛的阶梯状金属表面上的表面偏析。通过这个模型，我们在没有对3d、4d和5d金属的所有组合进行表面偏析的进一步DFT计算的情况下，估计了台阶修饰的稳定性。
