Influence of Framework n(Si)/n(Al) Ratio on the Nature of Cu Species in Cu‐ZSM‐5 for NH3‐SCR‐DeNOx. Issue 18 (11th July 2022)

• Record Type: Journal Article
• Authors: Jabłońska, Magdalena; Góra‐Marek, Kinga; Bruzzese, Paolo Cleto; Palčić, Ana; Pyra, Kamila; Tarach, Karolina; Bertmer, Marko; Poppitz, David; Pöppl, Andreas; Gläser, Roger
• Is Part Of: ChemCatChem. Volume 14:Issue 18(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-11
• Subjects: ZSM-5 -- copper species -- NH3-SCR -- 2D COS analysis; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.202200627
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: Nanosized Cu‐containing ZSM‐5 catalysts with different n (Si)/ n (Al) ratio of 18.9–50.5 were prepared by ion‐exchange. The physico‐chemical characterization clearly shows that the molar ratio of framework T atoms influences the nature and distribution of copper species. According to DR UV‐Vis, TPR‐H2, EPR, or FT‐IR spectroscopy analyses, the amount of aggregated copper species increases with increasing the framework n (Si)/ n (Al) ratio. Thus, the activity of the Cu‐containing ZSM‐5 with n (Si)/ n (Al) ratio of 47.0—50.5 in the selective catalytic NO reduction with NH3 (NH3 ‐SCR‐DeNO x ) significantly decreases compared to the other materials ( n (Si)/ n (Al) ratio of 18.9—19.6). The reaction mechanism has been discussed in light of the results of 2D COS (two‐dimensional correlation spectroscopy) analysis of IR spectra and catalytic properties of the zeolites. The results make evident that enhanced activity of Cu‐containing ZSM‐5 in NH3 ‐SCR‐DeNO x is correlated with the formation of different NO x − under the experimental conditions. Abstract : Copper‐containing zeolite : Changes in the zeolite preparation temperature result in the variation in the framework n (Si)/ n (Al) ratio, and thus, the nature of copper species in the Cu‐containing ZSM‐5. Activity and selectivity of catalysts in NH3 ‐SCR‐DeNO x drop due to the presence of aggregated copper species.