In-situ detection of chemisorbed CO on a polycrystalline platinum foil using infrared-visible sum-frequency generation

被引:31
作者
Harle, H [1 ]
Lehnert, A [1 ]
Metka, U [1 ]
Volpp, HR [1 ]
Willms, L [1 ]
Wolfrum, J [1 ]
机构
[1] Univ Heidelberg, Inst Phys Chem, D-69120 Heidelberg, Germany
关键词
D O I
10.1016/S0009-2614(98)00754-4
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Optical infrared-visible sum-frequency generation (SFG) surface vibrational spectroscopy was used for in-situ detection of CO adsorbed on a polycrystalline platinum foil in the range of 300-660 K at a CO pressure of 1 mbar under flow conditions. From the SFG spectra the frequency of the CO vibrationally resonant contribution was determined as a function of temperature. At 300 K a center-frequency of 2096 +/- 4 cm(-1) was obtained which is characteristic of the stretching vibration of CO 'on top'-bound at Pt terrace sites. At 660 K, the highest temperature where adsorbed CO could be detected on the foil, the center-frequency was 2057+/- 5 cm(-1) which can be attributed to CO molecules bound to defect-site PI atoms. Results obtained for the polycrystalline foil are compared with literature data for single crystal substrates. Results are presented where the SFG technique was applied for in-situ CO detection during heterogeneous CO oxidation on platinum over a pressure range of 10(-6)-10(3) mbar. (C) 1998 Elsevier Science B.V. All rights reserved.
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收藏
页码:26 / 32
页数:7
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