Abstract
CO在Pt-Fe催化剂的Pt/Fe/Pt(111)表面的吸附研究
CO Adsorption on Pt/Fe/Pt(111) Surface of Pt-Fe Model Catalysts
Received:October 26, 2018  
DOI:
中文关键词: 模型催化剂  次表层Fe结构  CO吸附  高分辨电子能量损失谱(HREELS)  脱附
英文关键词: model catalyst  Pt/Fe/Pt(111) structure  CO adsorption  high resolution energy loss spectroscopy (HREELS)  desorption
基金项目:沈阳农业大学天柱山学者计划、国家自然科学基金(No.21401131)。
Author NameAffiliationE-mail
MA Teng Institute of Science, Shenyang Agricultural University, Shenyang 110866, China mateng77@126.com 
JIAO Keran Institute of Science, Shenyang Agricultural University, Shenyang 110866, China  
XU Meiqi Institute of Science, Shenyang Agricultural University, Shenyang 110866, China  
CHEN Wei Institute of Science, Shenyang Agricultural University, Shenyang 110866, China  
WANG Yaqin Institute of Science, Shenyang Agricultural University, Shenyang 110866, China
School of Environmental and Chemical Engineering, Shenyang Ligong University, Shenyang 110159, China 
m15802436358@163.com 
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中文摘要:
      低温(110~130 K)下,将次表层Fe结构的Pt-Fe模型催化剂(即Pt/Fe/Pt(111)结构)暴露于不同量CO气体,经不同温度退火后,采用高分辨电子能量损失谱(HREELS)研究催化剂表面CO分子的振动谱。结果表明,当CO的暴露量低于0.2 L (Langmuir)时,Pt/Fe/Pt(111)表面只存在顶位吸附;当暴露量大于0.4 L,除了顶位吸附外,桥位吸附开始出现;顶位吸附分子的C-O键振动峰随着暴露量的增加不断向高波数方向偏移。退火温度影响Pt/Fe/Pt(111)表面CO的吸附形式,低于255 K时,顶位吸附分子的脱附速率大于桥位吸附分子;高于255 K时,桥位吸附分子的脱附速率较大,并先于顶位吸附的CO从表面完全脱附,其完全脱附温度比Pt(111)表面低50 K。
英文摘要:
      Vibration spectra of adsorbed CO molecules have been probed on subsurface Fe structure of Pt-Fe model catalysts, designated as Pt/Fe/Pt(111), after CO exposures at cyrogenic temperatures (110~130 K) and UHV annealing at stepwise temperatures, by high resolution energy loss spectroscopy (HREELS) technique. When the CO exposure was < 0.2 L, CO species were observed to adsorb only at top-sites. When the exposure was increased to around 0.4 L, CO species at bridge-sites were observed too. Furthermore, the peak of C-O bonds of top-site CO was observed to shift gradually towards higher wavenumbers. The adsorption of CO molecules on Pt-Fe/Pt(111) surface was also influenced by the annealing temperatures. At 255 K, the desorption rate of top-site CO was higher than that of bridge-site CO. While above 255 K, bridge-site CO molecules had a high desorption rate than that of top-site CO molecules, and the complete desorption temperature of bridge-site CO molecules is 50 K lower than that of Pt(111).
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