Abstract：
Structural evolution of solid catalyst surfaces induced by direct exposure to reaction gas has been extensively studied and is well understood. However, whether and how subsurface atomic structures are affected by the reaction atmosphere require further exploration. In this work, our results confirm that Cu clusters supported on FeO/Pt(111) (Cun/FeO/Pt) transform into surface CuCO complexes (CuCO/FeO/Pt) with exposure to CO at 78 K. Surprisingly, Cu clusters on Pt(111) buried under monolayer FeO film (FeO/Cun/Pt) can also transform into surface CuCO complexes on FeO/Pt(111) upon CO adsorption at 150 K. The place exchange of surface and subsurface Cu atoms at the FeO/Pt(111) surface can be mediated by exposing to CO at 150 K and keeping in ultrahigh vacuum at 300 K, alternatively. Calculation results reveal that CO adsorption induces restructuring of the FeO film above the Cu clusters, generating a diffusion channel for Cu atoms to pass through the FeO film and form surface CuCO, while Cu atoms remaining at the FeO-Pt interface are more thermodynamically favored without CO. Our work suggests that buried subsurface atoms may be involved in strong restructuring processes driven by reaction gas, which could strongly influence the catalytic performance.
摘要：
由直接暴露于反应气体引起的固体催化剂表面的结构演变已被广泛研究并得到充分理解。然而,地下原子结构是否以及如何受到反应气氛的影响需要进一步探索。在这项工作中,我们的结果证实，在78K下暴露于CO时，FeO/Pt（111）（Cun/FeO/Pt）上负载的Cu团簇转化为表面CuCO络合物（CuCO/FeO/Pt）。在150K下吸附CO时，埋在单层FeO膜（FeO/Cun/Pt）下的Pt（111）上的Cu团簇也可以转化为FeO/Pt（111）上的表面CuCO络合物。FeO/Pt（111）表面的表面和亚表面Cu原子的位置交换可以通过在150K下暴露于CO并在300K下保持在超高真空中来介导，或者。计算结果表明，CO吸附诱导了Cu团簇上方FeO膜的重构，生成Cu原子穿过FeO膜并形成表面CuCO的扩散通道，而保留在FeO-Pt界面处的Cu原子在没有CO的情况下在热力学上更有利。我们的工作表明，埋藏的地下原子可能参与了由反应气体驱动的强重组过程，这可能会强烈影响催化性能。
