Redox-Driven Migration of Copper Ions in the Cu-CHA Zeolite as Shown by the In Situ PXRD/XANES Technique.

Autor: Andersen CW; Center for Materials Crystallography, iNANO, Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus, Denmark., Borfecchia E; Haldor Topsøe A/S, Haldor Topsøes Allé 1, 2800, Kgs. Lyngby, Denmark.; Department of Chemistry, NIS and CrisDI interdepartmental centers, University of Turin, Via P. Giuria 7, 10125, Turin, Italy., Bremholm M; Center for Materials Crystallography, iNANO, Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus, Denmark., Jørgensen MRV; Center for Materials Crystallography, iNANO, Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus, Denmark.; MAX IV Laboratory, Fotongatan 2, 225 92, Lund, Sweden., Vennestrøm PNR; Haldor Topsøe A/S, Haldor Topsøes Allé 1, 2800, Kgs. Lyngby, Denmark., Lamberti C; Department of Chemistry, NIS and CrisDI interdepartmental centers, University of Turin, Via P. Giuria 7, 10125, Turin, Italy.; IRC 'Smart Materials', Southern Federal University, Zorge Street 5, 344090, Rostov-on-Don, Russia., Lundegaard LF; Haldor Topsøe A/S, Haldor Topsøes Allé 1, 2800, Kgs. Lyngby, Denmark., Iversen BB; Center for Materials Crystallography, iNANO, Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus, Denmark.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2017 Aug 21; Vol. 56 (35), pp. 10367-10372. Date of Electronic Publication: 2017 Jul 24.
DOI: 10.1002/anie.201703808
Abstrakt: Using quasi-simultaneous in situ PXRD and XANES, the direct correlation between the oxidation state of Cu ions in the commercially relevant deNO x NH 3 -SCR zeolite catalyst Cu-CHA and the Cu ion migration in the zeolitic pores was revealed during catalytic activation experiments. A comparison with recent reports further reveals the high sensitivity of the redox-active centers concerning heating rates, temperature, and gas environment during catalytic activation. Previously, Cu + was confirmed present only in the 6R. Results verify a novel 8R monovalent Cu site, an eventually large Cu + presence upon heating to high temperatures in oxidative conditions, and demonstrate the unique potential in combining in situ PXRD and XANES techniques, with which both oxidation state and structural location of the redox-active centers in the zeolite framework could be tracked.
(© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
Externí odkaz: