Université de Lyon, Institut de Chimie, Laboratoire de Chimie, Ecole Normale Supérieure de Lyon and CNRS, 46 Allée d'Italie, F-69364 Lyon Cedex 07, France.
J Chem Phys. 2012 Jan 28;136(4):044705. doi: 10.1063/1.3678864.
The growth of platinum on non-reduced CeO(2) (111) surface is studied by means of calculations based on the density functional theory. Particles of increasing size are formed on the oxide surface by incorporating the platinum atoms one by one until multilayer films are obtained. The main conclusion is that platinum atoms tend to maximize the number of metallic bonds and to approach the situation of the bulk, hence preferring films to particles, particles to isolated atoms, and a three-dimensional growth to a two-dimensional one. The supported particles and the films exhibit a contraction of the Pt-Pt distances, with respect to those of the Pt bulk, in order to match the ceria lattice. The density of states projected on the film surface platinum atoms shows important differences in shape and energy (lower d-band center) compared to the Pt(111) reference surface, which could be the major reason for the observed changes in catalytic reactivity when deposited particles are compared with single crystal surfaces.
采用基于密度泛函理论的计算方法研究了非还原 CeO(2)（111）表面上的铂生长。通过逐个引入铂原子，在氧化物表面上形成了尺寸不断增大的颗粒，直到获得多层膜。主要结论是，铂原子倾向于最大限度地增加金属键的数量，并接近体相的情况，因此优先形成薄膜而不是颗粒，颗粒又优先于孤立原子，而且三维生长优先于二维生长。负载的颗粒和薄膜表现出 Pt-Pt 距离的收缩，与 Pt 体相比，以匹配氧化铈晶格。与 Pt(111)参考表面相比，投影到薄膜表面铂原子的态密度在形状和能量（更低的 d 带中心）方面表现出重要差异，这可能是与沉积颗粒相比时观察到的催化反应性变化的主要原因。
