Winkler P, Zeininger J, Raab M, Suchorski Y, Steiger-Thirsfeld A, Stöger-Pollach M, Amati M, Gregoratti L, Grönbeck H, Rupprechter G
Institute of Materials Chemistry, TU Wien, Getreidemarkt 9, 1060, Vienna, Austria.
University Service Center for Transmission Electron Microscopy, TU Wien, Wiedner Hauptstraße 8-10, 1040, Vienna, Austria.
Nat Commun. 2021 Nov 11;12(1):6517. doi: 10.1038/s41467-021-26855-y.
Catalytic hydrogen oxidation on a polycrystalline rhodium foil used as a surface structure library is studied by scanning photoelectron microscopy (SPEM) in the 10 mbar pressure range, yielding spatially resolved X-ray photoemission spectroscopy (XPS) measurements. Here we report an observation of a previously unknown coexistence of four different states on adjacent differently oriented domains of the same Rh sample at the exactly same conditions. A catalytically active steady state, a catalytically inactive steady state and multifrequential oscillating states are simultaneously observed. Our results thus demonstrate the general possibility of multi-states in a catalytic reaction. This highly unusual behaviour is explained on the basis of peculiarities of the formation and depletion of subsurface oxygen on differently structured Rh surfaces. The experimental findings are supported by mean-field micro-kinetic modelling. The present observations raise the interdisciplinary question of how self-organising dynamic processes in a heterogeneous system are influenced by the permeability of the borders confining the adjacent regions.
在10毫巴压力范围内，利用扫描光电子显微镜（SPEM）对用作表面结构库的多晶铑箔上的催化氢氧化反应进行了研究，得到了空间分辨的X射线光电子能谱（XPS）测量结果。在此，我们报告了在完全相同的条件下，在同一铑样品相邻的不同取向区域上观察到四种不同状态的先前未知的共存现象。同时观察到催化活性稳态、催化非活性稳态和多频振荡状态。因此，我们的结果证明了催化反应中多态的普遍可能性。这种非常不寻常的行为是基于不同结构的铑表面上表面下氧的形成和消耗的特殊性来解释的。实验结果得到了平均场微观动力学模型的支持。目前的观察结果提出了一个跨学科问题，即非均相系统中的自组织动态过程如何受到限制相邻区域边界的渗透性的影响。
