Abstract

LOPEZ-CURIEL, Julio C.; HERNANDEZ-SALGADO, Gabriela I.; HERNANDEZ-TERAN, María E.  and  FUENTES, Gustavo A.. On the Structure-Activity Relationship for NO-SCR with NH₃ Catalyzed by Cu-exchanged Natural Chabazite and SSZ-13. J. Mex. Chem. Soc [online]. 2021, vol.65, n.1, pp.74-83.  Epub June 04, 2021. ISSN 1870-249X.  https://doi.org/10.29356/jmcs.v65i1.1267.

In spite of their similar structures, the catalytic properties of natural and synthetic (SSZ-13) Chabazite during the selective reduction of NO with NH3 have a different dependence on the Cu exchange level when tested under conditions equivalent to those found in Diesel vehicles. At low (1-2 wt.%) and high copper loadings (6-14 wt.%), their activities differ, because there are variations in the different species of Cu (Cu+, Cu2+, Cu-O-Cu) detected by UV-Vis. At intermediate Cu loadings (2-3 wt.%) they have similar high activities, reaching 100 % conversion. High deNOx activity per Cu site appears to correlate with the predominance of charge compensation Cu2+ species over CuOx moieties. There are changes in the distribution of Cu moieties during operation of both catalysts, evidenced by DR-UV-Vis.

Keywords : Selective catalytic reduction of NO; Cu-CHA; natural chabazite; SSZ-13; UV-Vis.

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