2017-Sustainable Industrial Processing Summit
SIPS 2017 Volume 5. Marquis Intl. Symp. / New and Advanced Materials and Technologies
| Editors: | Kongoli F, Marquis F, Chikhradze N |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2017 |
| Pages: | 590 pages |
| ISBN: | 978-1-987820-69-0 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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FTIR Spectroscopy for Characterization of Surface Properties of Disperse Materials
Alexey Tsyganenko1;1ST.PETERSBURG STATE UNIVERSITY, St. Petersburg, Russian Federation;
Type of Paper: Keynote
Id Paper: 252
Topic: 43
Abstract:
Surfaces and interfaces are everywhere: in the ground, seawater, atmosphere, space, and even in the living organisms. Vibrational spectroscopy is the most powerful non-destructive method for surface characterization. Spectra of surface functional groups and adsorbed test molecules provide information on the nature of active sites, their strength and concentration. Variable temperature spectroscopy data enable us to study thermodynamics of surface processes and measure the energy or entropy of adsorption. At low-temperatures it is possible to see the spectra of CO, NO, H2 N2 or other simple molecules that do not adsorb at room temperature. Using low-temperature adsorption of weak CH proton-donating molecules such as CHF3, we can characterize the basicity of surface electron-donating sites. Carrying out simultaneous measurements of spectra, pressure and temperatures one can obtain spectrokinetic data and get information about the height of activation barriers of surface reactions. To trap the unstable intermediates of catalytic processes we can follow spectra evolution with temperature and observe the chain of reactant transformations. In particular, the method can be applied to the studies of photocatalytic reactions, modeling the reactions at the surface of atmospheric aerosol particles. The structure of intermediates can be clarified using isotopic substitution, then the detailed mechanism of catalytic processes could be established.
Some adsorption products cannot be stabilized at low temperatures, but arise at the surface as a result of thermal excitation. So, CO forms with the cations in zeolites two kinds of complexes. Besides the usual C-bonded structure the energetically less favorable O-bonded species arise and exist in thermodynamic equilibrium with usual form. Such linkage isomerism was established for some other adsorbed species, such as cyanide ion CN- produced by HCN dissociation.
FTIR spectra are sensitive to lateral interactions between the adsorbed species, which shift the bands of test molecules or complicate their contours. Co-adsorption of acidic and basic molecules leads to mutual enhancement of adsorption. Acidity of surface sites can be increased by adsorbed acidic molecules, this is consistent with superacidity of oxides doped with SO42-. By means of isotopic dilution this static interaction can be distinguished from the dynamic one. The latter, called also as resonance dipole-dipole (RDD) interaction, accounts for the vibrational energy exchange in the adsorbed layer. Its spectral manifestation provide additional information on the geometry of surfaces.
Quantitative spectral analysis of surface sites is not possible without the knowledge of absorption coefficients of test molecules. Quantum chemical calculations and electrostatic approach predict the correlation between the frequency shifts on adsorption and the absorption coefficients, in a fair agreement with the experimental data.
Keywords:
Environment; Nanomaterials;References:
[1] G. Ewing: Excitons and High Resolution Infrared Spectroscopy. In: Adsorption on Ordered Surfaces of Ionic Solids and Thin Films. (Springer Series in Surface Science. Vol. 33.). Freund H.-J. and Umbach E (eds.) Berlin-Heidelberd, Springer Verlag, (1993), 57-67.[2] W. Ho: Single-Molecule Chemistry, Journal of Chemical Physics, 117 (2002), 11033-11061.
[3] A. Tsyganenko: Variable Temperature IR Spectroscopy in the Studies of Oxide Catalysts, Topics in Catalysis, 56 (2013), 905-913.
[4] T. Rodionova, A. Tsyganenko and V. Filimonov: Infrared Study of Low-Temperature CO Adsorption on Metal Oxides, Adsorbtsiya i Adsorbenty, 10 (1982), 33(in Russ).
[5] M. Zaki, H. Knozinger: Characterization of Oxide Surfaces by Adsorption of Carbon Monoxyde - a Low Temperature Infrared Spectroscopy Study, Spectrochimica Acta - Part A Molecular Spectroscopy, 43 (1987), 1455-1459.
[6] A. Tsyganenko, E. Kondratieva, V. Yanko, P. Storozhev: FTIR Study of CO Adsorption on Basic Zeolites, Journal of Materials Chemistry, 16 (2006), 2358-2363.
[7] M. Babaeva, A. Tsyganenko: Infrared Spectroscopic Evidence for the Formation of Carbonite CO22- Ions in CO Interaction with Basic Oxide Surfaces, Reaction Kinetics and Catalysis Letters, 34 (1987), 9-14.
[8] A. Tsyganenko, E. Escalona Platero, C. Otero Areán, E. Garrone and A. Zecchina: Variable Temperature IR Spectroscopic Studies of CO Adsorbed on Na-ZSM-5 and Na-Y Zeolites, Catalysis Letters, 61 (1999), 187-192.
[9] P. Storozhev, C. Otero Areán, E. Garrone, P. Ugliengo, V. Ermoshin and A. Tsyganenko: FTIR Spectroscopic and ab initio Evidence for the Amphipathic Character of CO Bonding with Silanol Groups, Chemical Physics Letters, 374 (2003), 439-445.
[10] R. Belykh, M. Maevskaya, I. Krauklis and A. Tsyganenko: Linkage Isomerism of CO Adsorbed on Alkali Halides, Journal of Physical Chemistry A, 119 (2015), 2363-2370.
[11] A. Tsyganenko, A.M.Chizhik and A.I.Chizhik: A FTIR Search for Linkage Isomerism of CN- Ions on Oxides and Zeolites, Physical Chemistry Chemical Physics, 12 (2010), 6387-6395.
[12] Tsyganenko, N. Zakharov and P. Murzin: CHF3 as a Probe for Surface Basicity, Catalysis Today, 226 (2014), 73–80.
[13] E. Kondratieva, O. Manoilova and A. Tsyganenko: Integrated Extinction Coefficient of Adsorbed CO, Kinetics and Catalysis, 49 (2008), 451-456.
[14] A. Tsyganenko, L. Denisenko, S. Zverev and V. Filimonov: Infrared Study of Lateral Interactions between Carbon Monoxide Molecules Adsorbed on Oxide Catalysts, Journal of Catalysis, 94 (1985), 10-15.
[15] Tsyganenko, S. Zverev: Mechanism of Lateral Interactions between Molecules Adsorbed on Oxide Surfaces, Reaction Kinetics and Catalysis Letters, 36 (1988), 269-274.
[16] Tsyganenko, E. Storozheva, O. Manoilova, T. Lesage, M. Daturi, J.-C. Lavalley: Brønsted Acidity of Silica Silanol Groups Induced by Adsorption of Acids, Catalysis Letters, 70 (2000), 159-163.
[17] Dobrotvorskaia, T. Kolomiitsova, S. Petrov, D. Shchepkin, A. Tsyganenko. Effect of Resonance Dipole-Dipole Interaction on Spectra of Adsorbed SF6 Molecules, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 148 (2015), 271–279.
[18] Dobrotvorskaia, A. Gatilova, P. Murzin, A. Rudakova, D. Shchepkin, A. Tsyganenko: Effect of Resonance Dipole-Dipole Interaction on the Spectra of Adsorbed CF4, Journal of Photochemistry and Photobiology A: Chemistry, 000 (2017) 000-000 in print.