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NH$_{3}$-SCR over V-W/TiO$_{2}$ Investigated by Operando X-ray Absorption and Emission Spectroscopy

Doronkin, D. E.; Benzi, F.; Zheng, L.; Sharapa, D. I.; Amidani, L.; Studt, F.; Roesky, P. W.; Casapu, M.; Deutschmann, O.; Grunwaldt, J.-D.

Abstract:
V–W/TiO$_{2}$-based catalysts, which are used for the removal of NO$_{x}$ from the exhaust of diesel engines and stationary sources via selective catalytic reduction with NH$_{3}$ (NH$_{3}$-SCR), were studied by operando X-ray absorption spectroscopy (XAS) and emerging photon-in/photon-out techniques. In order to minimize the influence of highly X-ray absorbing tungsten and the fluorescence of titanium, we used a high-energy-resolution fluorescence setup that is able to separate efficiently the V Kβ$_{1,3}$ emission lines and additionally allows to record valence-to-core (vtc) X-ray emission lines. High-energy resolution fluorescence-detected XAS (HERFD-XAS) and vtc X-ray emission spectroscopy (vtc-XES) proved to be the only way to perform an operando V K edge X-ray spectroscopic study on industrially relevant V–W/TiO$_{2}$ catalysts so far. The V–W/TiO$_{2}$ and V/TiO$_{2}$ samples synthesized by incipient wetness impregnation and grafting exhibited high activity toward NH$_{3}$-SCR. Raman spectroscopy showed that they mainly contained highly dispersed, isolated, and polymeric V-oxo species. HERFD-XAS and XES identified redox cycling of vanadium species between V$^{4+}$ and V$^{5+}$. ... mehr

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Postprint §
DOI: 10.5445/IR/1000096219/post
Veröffentlicht am 08.01.2020
Originalveröffentlichung
DOI: 10.1021/acs.jpcc.9b00804
Scopus
Zitationen: 14
Dimensions
Zitationen: 15
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Anorganische Chemie (AOC)
Institut für Katalyseforschung und -technologie (IKFT)
Institut für Technische Chemie und Polymerchemie (ITCP)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 13.06.2019
Sprache Englisch
Identifikator ISSN: 1932-7447, 1932-7455
KITopen-ID: 1000096219
HGF-Programm 43.22.02 (POF III, LK 01) Nanocatalysis
Erschienen in The journal of physical chemistry <Washington, DC> / C
Verlag American Chemical Society (ACS)
Band 123
Heft 23
Seiten 14338-14349
Vorab online veröffentlicht am 24.05.2019
Nachgewiesen in Web of Science
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Scopus
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