کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9595060 1507973 2005 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Interpreting intensities in vibrational sum frequency generation (SFG) spectroscopy: CO adsorption on Pd surfaces
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Interpreting intensities in vibrational sum frequency generation (SFG) spectroscopy: CO adsorption on Pd surfaces
چکیده انگلیسی
The lineshape and intensity of SFG signals of CO adsorbed on supported Pd nanoparticles and Pd(1 1 1) are analyzed. For CO/Pd(1 1 1) nearly symmetric lorentzian lineshapes were observed. Applying two different visible wavelengths for excitation, asymmetric lineshapes observed for the CO/Pd/Al2O3/NiAl(1 1 0) system are explained by a lower resonant and a higher non-resonant SFG signal and a change in the phase between resonant and non-resonant signals, most likely originating from an interband transition in the NiAl substrate. The relative intensity of different CO species (hollow, bridge, on-top) was modeled by DFT calculations of IR transition moments and Raman activities. While the (experimental) sensitivity of SFG towards different CO species strongly varies, the calculated IR and Raman activities are rather similar. The inability to exactly reproduce experimental SFG intensities suggests a strong coverage dependence of Raman activities or that non-linear effects occur that can currently not be properly accounted for.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface Science - Volume 586, Issues 1–3, 20 July 2005, Pages 146-156
نویسندگان
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