Infrared Reflection−Absorption Study of Carbon Monoxide Adsorption on Fe/Pt(111) Bimetallic Surfaces
Infrared Reflection−Absorption Study of Carbon Monoxide Adsorption on Fe/Pt(111) Bimetallic Surfaces
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DOI：
10.1021/jp712095w
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发表时间：
2008-05
影响因子：
3.7
通讯作者：
T. Wadayama;H. Osano;T. Maeyama;H. Yoshida;K. Murakami;Naoki Todoroki;S. Oda
中科院分区：
文献类型：
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作者：
T. Wadayama;H. Osano;T. Maeyama;H. Yoshida;K. Murakami;Naoki Todoroki;S. Oda
采用红外反射-吸收光谱（IRRAS）研究了在343、403和473 K的衬底温度下，采用分子束外延工艺制备的亚单层（ML）至1.0 ML厚的Fe沉积Pt（111）双金属表面，即Fex/Pt(111) （x，以ML为单位的Fe厚度）上一氧化碳（CO）的吸附。1.0 L CO在室温下暴露于干净的Pt（111）中，在2093和1855 cm−1处产生线性键合和桥键合的CO - Pt带。Fex/Pt(111) CO暴露表面的CO- Pt波段强度随Fe厚度的增加而降低。在343 K沉积的Fe1.0ML/Pt（111）中，CO - Pt谱带几乎消失，1950 cm - 1的桥键CO - Fe谱带占主导地位。此外，Fe沉积在2060 cm−1附近形成了新的吸收带；在473 K下沉积的Fe0.5ML/Pt（111）中，该条带占优势。在473 K Pt（111）上沉积1 ml厚的Fe，在2050 cm−1处产生较弱的、较宽的吸收。
Infrared reflection−absorption spectroscopy (IRRAS) was used to investigate carbon monoxide (CO) adsorption on sub-monolayer (ML)-thick to 1.0 ML-thick Fe deposited Pt(111) bimetallic surfaces, that is, Fex/Pt(111) (x, Fe thickness in ML units), fabricated using molecular beam epitaxy at substrate temperatures of 343, 403, and 473 K. The 1.0 L CO exposure to a clean Pt(111) at room temperature yielded linearly bonded and bridge-bonded CO−Pt bands at 2093 and 1855 cm−1. The CO−Pt band intensities for the CO-exposed surfaces of the Fex/Pt(111) decreased with increasing Fe thickness. The CO−Pt bands almost disappeared, and the bridge-bonded CO−Fe band at 1950 cm−1 dominated the spectra for the Fe1.0ML/Pt(111) deposited at 343 K. In addition, the Fe deposition brought about a new absorption band at around 2060 cm−1; this band is predominant for the Fe0.5ML/Pt(111) deposited at 473 K. The 1 ML-thick Fe deposition onto the 473 K Pt(111) engenders less-intense, rather broad absorption at 2050 cm−1, accompanied b...