Adsorption of carbon monoxide on Au(110)-(1 x 2)
Adsorption of carbon monoxide on Au(110)-(1 x 2)
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DOI：
10.1016/s0039-6028(03)00595-8
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发表时间：
2003-06-20
期刊：
影响因子：
1.9
通讯作者：
Christmann, K
中科院分区：
文献类型：
--
作者：
Gottfried, JM;Schmidt, KJ;Christmann, K
用TDS、UPS、DeltaPhi、NEXAFS和LEED等方法研究了28 ~ 300 K温度范围内CO在金（110）-（1x 2）表面上的吸附.在150 K以下，CO以非解离吸附方式吸附，初始吸附概率较高（28 K时S-0 = 0.9）。对于Theta（CO）-> 0，CO吸附的等排热为59 kJ/mol，并且随着覆盖度强烈降低，表明弱的化学吸附和大量的CO-CO排斥，与TDS结果一致。热脱附光谱显示至少五个脱附状态对应于38和8 kJ/mol之间的脱附能量。根据TDS，化学吸附和物理吸附的CO共存于第一层中，这一结果得到了UV光电子能谱的证实。CO吸附对DeltaPhi具有复杂的影响，并导致在单层覆盖下的功函数降低约0.95 eV。TDS和熵的测量表明，在160 K的化学吸附CO的状态是最好的二维气体的模型来描述。在整个覆盖度和温度范围内没有观察到有序的CO覆盖层结构。(C)2003 Elsevier Science B. V.保留所有权利。
The adsorption of carbon monoxide on a gold (11 0)-(l x 2) surface was studied between 28 and 300 K by means of TDS, UPS, DeltaPhi, NEXAFS, and LEED. Below 150 K, CO adsorbs non-dissociatively with high initial sticking probability (S-0 = 0.9 at 28 K). The isosteric heat of CO adsorption is 59 kJ/mol for Theta(CO) --> 0 and decreases strongly with coverage, indicating weak chemisorption and substantial CO-CO repulsion, in agreements with TDS results. Thermal desorption spectra show at least five desorption states corresponding to desorption energies between 38 and 8 kJ/mol. According to TDS, chemisorbed and physisorbed CO coexist in the first layer, a result that is corroborated by UV photoemission spectra. CO adsorption has a complex influence on DeltaPhi and leads to a work function reduction of -0.95 eV at monolayer coverage. TDS and entropy measurements suggest that the state of chemisorbed CO at 160 K is best described by the model of a two-dimensional gas. No ordered CO overlayer structures were observed in the whole coverage and temperature range. (C) 2003 Elsevier Science B.V. All rights reserved.