Structural snapshots of the SCR reaction mechanism on Cu-SSZ-13.
نویسندگان
چکیده
The structure of copper sites in Cu-SSZ-13 during NH3-SCR was unravelled by a combination of novel operando X-ray spectroscopic techniques. Strong adsorption of NH3 on Cu, its reaction with weakly adsorbed NO from the gas phase, and slow re-oxidation of Cu(I) were proven. Thereby the SCR reaction mechanism is significantly different to that observed for Fe-ZSM-5.
منابع مشابه
Synthesis and functionalization of SSZ-13 as an NH3-SCR catalyst
Hydrothermal synthesis of Na-SSZ-13 using a low concentration of the structure-directing agent N,N,N-trimethyl-1-adamantanimonium hydroxide and functionalization of the SSZ-13 framework through the introduction of Cu and Fe via ion exchange have been carried out. The prepared samples were characterized by XRD, SEM, and UV-vis spectroscopy, N2 sorption, XRF and NH3-TPD. It was found that relativ...
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Cu-SSZ-13 has been characterized by different spectroscopic techniques and compared with Cu-ZSM-5 and Cu-β with similar Si/Al and Cu/Al ratios and prepared by the same ion exchange procedure. On vacuum activated samples, low temperature FTIR spectroscopy allowed us to appreciate a high concentration of reduced copper centres, i.e. isolated Cu(+) ions located in different environments, able to f...
متن کاملRevisiting the nature of Cu sites in the activated Cu-SSZ-13 catalyst for SCR reaction† †Electronic supplementary information (ESI) available: experimental section (sample description, in situ FTIR spectroscopy, synchrotron characterization, DFT-based analysis of XAS and XES data); XAS of hydrated Cu-SSZ-13; reversibility of the Cu(i) ↔ Cu(ii) redox chemistry and extra-ligand loss process upon high-temperature gas-flow switching; full report on DFT-optimized geometries; full report on EXAFS fitting results on O2-activated Cu-SSZ-13; EXAFS spectra for a low Cu-loading Cu-SSZ-13 sample after O2-activation at 400 °C. See DOI: 10.1039/c4sc02907k Click here for additional data file.
Department of Chemistry and INSTM Refe Giuria 7, 10125 Turin, Italy. E-mail: carlo.l NIS Centre of Excellence, University of Turi Haldor Topsøe A/S, Nymøllevej 55, 2800 Kg CrisDI Center of Crystallography, Universit Southern Federal University, Zorge street 5 † Electronic supplementary information (sample description, in situ FTIR spectr DFT-based analysis of XAS and XES reversibility of the Cu...
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عنوان ژورنال:
- Chemical communications
دوره 51 44 شماره
صفحات -
تاریخ انتشار 2015