College of Physics and Information Engineering, Henan Normal University, Xinxiang, Henan 453007, People's Republic of China.
J Phys Condens Matter. 2010 Dec 1;22(47):475003. doi: 10.1088/0953-8984/22/47/475003. Epub 2010 Nov 5.
Results from first principles calculations present a rather clear atomic and electronic level picture of the interaction of single noble metals (NM: Pd, Pt and Rh) and the corresponding NM(4) clusters with a CeO(2)(111) surface. The most preferable adsorption sites for both the Pd and Pt adatoms are the surface O-bridge sites, while the Rh adatom prefers to stay at the O-hollow site. The Rh adatom shows much stronger interaction with the CeO(2)(111) surface than the Pd and Pt adatoms do, while the Pd adatom has the smallest adsorption energy. The dependence of the Rh/ceria interfacial properties on the value of the Hubbard U-term was tested systematically. The small clusters show stronger interaction than the corresponding single NM adatoms on the CeO(2)(111) surface. The reaction of [Formula: see text] was found for both the single NM adatoms and the small cluster adsorbate, indicating that NM adsorbates were mainly oxidized by the surface Ce ions with obvious charge transfer from NM to the CeO(2)(111) surface. The three base atoms of the small clusters that bonded with the CeO(2)(111) surface showed positive charges, while the top metal atoms of the NM(4) clusters had a small negative charge.
基于第一性原理的计算结果清晰地呈现出单贵金属（NM：Pd、Pt 和 Rh）与相应的 NM（4）团簇与 CeO（2）（111）表面相互作用的原子和电子水平图景。对于 Pd 和 Pt 原子，最优先的吸附位置是表面 O-桥位，而 Rh 原子更喜欢占据 O-空位。Rh 原子与 CeO（2）（111）表面的相互作用比 Pd 和 Pt 原子强得多，而 Pd 原子的吸附能最小。Rh/氧化铈界面性质对 Hubbard U 项值的依赖性进行了系统测试。小团簇在 CeO（2）（111）表面上的相互作用比相应的单 NM 原子强。对于单 NM 原子和小团簇吸附物，都发现了 [Formula: see text]反应，表明 NM 吸附物主要被表面 Ce 离子氧化，从 NM 到 CeO（2）（111）表面有明显的电荷转移。与 CeO（2）（111）表面结合的小团簇的三个基原子带正电荷，而 NM（4）团簇的顶部金属原子带小的负电荷。
