Manipulating the charge state of Au clusters on rutile TiO2(110) single crystal surfaces through molecular reactions probed by infrared spectroscopy
Manipulating the charge state of Au clusters on rutile TiO2(110) single crystal surfaces through molecular reactions probed by infrared spectroscopy
复制标题
通过红外光谱探测的分子反应操纵金红石 TiO2(110) 单晶表面上金簇的电荷状态
DOI：
10.1039/c6cp02324j
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发表时间：
2016-07-14
影响因子：
3.3
通讯作者：
Xu, Mingchun
中科院分区：
文献类型：
--
作者：
Cao, Yunjun;Hu, Shujun;Xu, Mingchun
以CO为探针，用紫外-红外光谱（UHV-FTIRS）研究了沉积在金红石型TiO 2（110）单晶表面的Au团簇的电荷状态。沉积在TiO 2（110）表面上的Au团簇是电中性的，其吸附CO的振动频率为2105-2112 cm（-1），取决于Au的覆盖度。Au/TiO_2（110）在400 K的温和氧气氛中退火，使TiO_2（110）表面和Au团簇上CO的振动频率仅蓝移2-3 cm（-1）。NO暴露使吸附在界面附近的Au原子上的CO振动频率蓝移16-26 cm（-1），使吸附在Au团簇顶部的CO振动频率蓝移3-4 cm（-1）。作为来自Au的强电荷转移的受体，在裸TiO 2（110）表面的小部分上通过（NO）（2）-> N2 O + O-a反应产生的O-a原子驻留在Au/TiO 2（110）界面周边周围，导致中性Au-0成为阳离子Au delta+状态。这是一种调控氧化物表面Au团簇电荷状态的新方法，可能有助于调控氧化物负载金属体系的催化氧化还原反应。
The charge state of Au clusters deposited on rutile TiO2(110) single crystal surfaces was studied by UHV-FTIRS using CO as a probe. The as-deposited Au clusters on oxidized TiO2(110) surfaces are electrically neutral and are identified by the 2105-2112 cm(-1) vibrational frequency of adsorbed CO depending on Au coverage. Annealing Au/TiO2(110) in a moderate O2 atmosphere at 400 K blue shifts the CO vibrational frequency by only 2-3 cm(-1) both on bare TiO2(110) surfaces and on Au clusters. However, NO exposure blue shifts the CO vibrational frequency by 16-26 cm(-1) for CO adsorbed on Au atoms near the interface and by 3-4 cm(-1) for CO adsorbed on top of Au clusters. As the acceptors of the intense charge transfer from Au, the O-a atoms generated through (NO)(2) -> N2O + O-a reactions on the small fraction of the bare TiO2(110) surface reside around the Au/TiO2(110) interface perimeter, causing the neutral Au-0 to be cationic Au delta+ states. This is a new approach to manipulate the charge state of Au clusters on oxide surfaces, which may be helpful in regulating the catalytic redox reactions on oxide supported metal systems.