纳米团簇
X射线光电子能谱
吸附
石墨烯
催化作用
材料科学
结合能
反应性(心理学)
星团(航天器)
活化能
光电发射光谱学
化学
物理化学
结晶学
纳米技术
化学工程
有机化学
原子物理学
物理
工程类
病理
计算机科学
程序设计语言
替代医学
医学
作者
Karin Gotterbarm,Florian Späth,Udo Bauer,Carina Bronnbauer,Hans‐Peter Steinrück
标识
DOI:10.1021/acscatal.5b00245
摘要
Nanocluster arrays on graphene (Gr) are intriguing model systems for catalysis. We studied the adsorption and oxidation of CO on Pt/Gr/Rh(111) with synchrotron-based high-resolution X-ray photoelectron spectroscopy. On the nanoclusters, CO is found to adsorb at three different sites: namely, on-top, bridge, and step. The C 1s spectra exhibit remarkable similarities to those on the stepped Pt(355) surface. Similar to the case for stepped Pt surfaces, a clear preference for the adsorption on the step sites is found, while the preference for the adsorption on the on-top site over the bridge site on the terraces is much less pronounced in comparison to that on Pt single crystals. Temperature-programmed X-ray photoelectron spectroscopy revealed an enhanced binding energy for the cluster step sites, similar to the situation on stepped Pt surfaces. The oxidation of CO on graphene-supported Pt nanoclusters follows a pseudo-first-order rate law. Applying an Arrhenius analysis, we found an activation energy of 13 ± 4 kJ/mol, which is much smaller than that on Pt(111), due to the more reactive step and kink sites on the nanoclusters.
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