Emergence of Subsurface Oxygen on Rh(111)
Emergence of Subsurface Oxygen on Rh(111)
复制标题
Rh(111) 上地下氧的出现
DOI：
10.1021/acs.jpclett.1c01820
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Killelea, Daniel R.
中科院分区：
文献类型：
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作者：
Turano, Marie E.;Jamka, Elizabeth A.;Gillum, Maxwell Z.;Gibson, K. D.;Farber, Rachael G.;Walkosz, Weronika;Sibener, S. J.;Rosenberg, Richard A.;Killelea, Daniel R.
过渡金属表面上的氧原子在通常用于非均相催化氧化反应的要求压力和温度下是高度移动的。这种流动性允许氧原子的快速表面扩散，以及吸收到次表面和重新出现到表面，导致可变的反应性。亚表面氧原子在氧化金属催化剂的化学中起着独特的作用，但人们对亚表面氧是如何形成或返回表面的知之甚少。此外，如果表面和次表面之间的氧扩散是由缺陷介导的，则由于出现位点附近的氧浓度升高，将存在表面化学的局部变化。我们观察到，氧原子出现优先沿着表面相之间的边界和表面氧化物分解之前，表面下的氧耗尽。
Oxygen atoms on transition metal surfaces are highly mobile under the demanding pressures and temperatures typically employed for heterogeneously catalyzed oxidation reactions. This mobility allows for rapid surface diffusion of oxygen atoms, as well as absorption into the subsurface and reemergence to the surface, resulting in variable reactivity. Subsurface oxygen atoms play a unique role in the chemistry of oxidized metal catalysts, yet little is known about how subsurface oxygen is formed or returns to the surface. Furthermore, if oxygen diffusion between the surface and subsurface is mediated by defects, there will be localized changes in the surface chemistry due to the elevated oxygen concentration near the emergence sites. We observed that oxygen atoms emerge preferentially along the boundary between surface phases and that subsurface oxygen is depleted before the surface oxide decomposes.