Characterization of oxide-supported Cu by infrared measurements on adsorbed CO
نویسندگان
چکیده
• Dipole coupling is critical for understanding IR spectra of adsorbed CO on Cu. Surface protrusions dominate the contribution from Cu surface. The C-O frequency in supported determined by underlying support. Support dependent charging surface can explain shifts. regulates adsorbate population that sustain. Infrared spectroscopy chemisorbed Raney and materials with dispersed as nanoparticles oxide supports was used to evaluate support effects properties. (? ) sensitive charge adsorption site ? being high + , intermediate 0 low ? whereby this method probe state reference demonstrates complex analysis band intensity, which be susceptible dipole coupling. This means most intense bands may higher strengthened such rather than arising abundant sites. major attributable metallic follows order: Cu/SiO 2 > Cu/Al O 3 Cu/TiO . Given charge-frequency relationship these support-dependent shifts are attributed changes caused effects. more electron deficient enriched For Cu/ZnO(/Al samples, important industrial methanol synthesis catalysts, assignments complicated a sites connected ZnO matrix. However, has spectral feature at 2065-68 cm ?1 lower observed single crystal studies literature thus indicative negative systems. Experiments co-adsorption electron-withdrawing formate Cu/ZnO show upwards increasing HCOO coverage. illustrates donated adsorbate, result co-adsorbed experiences depleted yields affect interaction adsorbates metal thereby impact catalytic properties Dilution samples KBr, been many literature, had pronounced spectra. presence KBr leads an increase transfer bromine species sample.
منابع مشابه
Unusual infrared spectrum of ethane adsorbed by gallium oxide.
The present study reports an unusual diffuse reflection Fourier transform (DRIFT) spectrum of ethane adsorbed by gallium oxide. One of the stretching C-H bands in this spectrum with a maximum at 2753 cm(-1) is more than by 100 cm(-1) shifted toward lower frequencies in comparison with gaseous ethane. In addition, the relative intensity of this band is unusually high. This indicates a very stron...
متن کاملStructural and electronic properties of CO molecule adsorbed on the TiO2 supported Au overlayers: Insights from density functional theory computations
We have examined the adsorption behaviors of carbon monoxide (CO) molecule on TiO2 anatase supported Au overlayers. The results of density functional theory (DFT) calculations were used in order to gain insights into the effects of the adsorption of CO molecules on the considered hybrid nanostructures. We have investigated different adsorption geometries of CO over the nanoparticles....
متن کاملCopper-on-copper homoepitaxy studied by infrared spectroscopy of adsorbed CO.
Infrared spectroscopy of adsorbed CO was used to characterize the dependence of surface structure on deposition temperature during homoepitaxial growth on Cu(100). Intensity borrowing due to dipole coupling greatly enhances the absorption signal due to defect-bonded CO, making it possible to detect and quantify defect concentrations at the level of a few percent. For deposition temperatures bet...
متن کاملIndoor wireless infrared channel characterization by measurements
Use of infrared light for indoor wireless communications has received considerable attention recently. In this paper, we present results obtained from a large set of measurements performed at the University of Ottawa. We investigate impacts of receiver rotation and shadowing on the properties of indoor infrared channels. This paper contains a description of a measurement system developed and us...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Surface Science
سال: 2021
ISSN: ['1879-2758', '0039-6028']
DOI: https://doi.org/10.1016/j.susc.2020.121725