Bistability and formation of low work function areas in the O2+H2 reaction on a Rh(111) surface
Bistability and formation of low work function areas in the O2+H2 reaction on a Rh(111) surface
复制标题
Rh(111) 表面 O2 H2 反应中的双稳定性和低功函数区域的形成
DOI：
--
复制
发表时间：
2000
期刊：
影响因子：
--
通讯作者：
R. Imbihl
中科院分区：
文献类型：
--
作者：
A. Schaak;R. Imbihl
用光电子发射显微镜（PEEM）作为空间分辨方法，在10 - 6-10 - 5 mbar范围内研究了Rh（111）上的O2+H2催化反应。根据样品的预处理，其中样品在T=770 K下暴露于pO 2 =2×10−4 mbar的不同时间（tOX），发现了不同的动力学行为。对于tOX=12 h，我们发现了简单的反应前沿，其引发了非反应性高氧覆盖状态和反应性几乎裸露表面之间的转变。 对于tOX=36小时低功函数（WF）的地区，在该地区的两个反应前线碰撞。 对于很长的氧气预处理与tOX=48小时的形成的二次锋向后行驶的两个主锋碰撞的区域被认为是。 在吸附和滴定实验中研究了已被暂时分配给地下氧的低WF区域的性质。
The catalytic O2+H2 reaction on Rh(111) has been investigated in the 10−6–10−5 mbar range using photoelectron emission microscopy (PEEM) as spatially resolving method. Depending on the pretreatment of the sample in which the sample was exposed to pO2=2×10−4 mbar at T=770 K for varying times (tOX) different dynamic behavior was found. For tOX=12 h we found simple bistable behavior with reaction fronts initiating transitions between an unreactive high oxygen coverage state and a reactive almost bare surface. For tOX=36 h low work function (WF) areas developed in the area where two reaction fronts collided. For very long oxygen pretreatments with tOX=48 h the formation of secondary fronts traveling backwards from the area where two primary fronts collided were seen. The properties of the low WF areas which have been tentatively assigned to subsurface oxygen were studied in adsorption and titration experiments.