The influence of CO adsorption on the surface composition of cobalt/palladium alloys
The influence of CO adsorption on the surface composition of cobalt/palladium alloys
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DOI：
10.1016/j.susc.2015.08.004
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发表时间：
2016-04-01
期刊：
影响因子：
1.9
通讯作者：
Baddeley, C. J.
中科院分区：
文献类型：
--
作者：
Murdoch, A.;Trant, A. G.;Baddeley, C. J.
由气相物种吸附引起的偏析可以强烈地影响双金属表面的组成，因此在影响多相催化反应中起着重要作用。在钴催化剂中添加钯可以促进费托催化反应。我们用反射吸收红外光谱和中能离子散射相结合的方法研究了CO在Pd{111}上的双金属表面上的吸附。吸附CO的振动频率提供了有关CO吸附位置的重要信息，中能离子散射探测了CO暴露前后的表面成分。我们证明了钴的偏析是由CO吸附引起的，并根据CO在不同表面吸附位置的吸附强度对这些观察结果进行了合理的解释。(C)2015爱思唯尔B.V.保留所有权利。
Segregation induced by the adsorption of gas phase species can strongly influence the composition of bimetallic surfaces and can therefore play an important role in influencing heterogeneous catalytic reactions. The addition of palladium to cobalt catalysts has been shown to promote Fischer Tropsch catalysis. We investigate the adsorption of CO onto bimetallic CoPd surfaces on Pd{111} using a combination of reflection absorption infrared spectroscopy and medium energy ion scattering. The vibrational frequency of adsorbed CO provides crucial information on the adsorption sites adopted by CO and medium energy ion scattering probes the surface composition before and after CO exposure. We show that cobalt segregation is induced by CO adsorption and rationalise these observations in terms of the strength of adsorption of CO in various surface adsorption sites. (C) 2015 Elsevier B.V. All rights reserved.