Study of the surface species formed from the interaction of NO and CO with copper ions in ZSM-5 and Y zeolites

• Published in: Applied surface science 1994-08, Vol.78 (4), p.477-484
• Main Authors: Márquez-Alvarez, C., McDougall, G.S., Guerrero-Ruiz, A., Rodríguez-Ramos, I.
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts: preparations and properties; Chemistry; Exact sciences and technology; General and physical chemistry; Ion-exchange; Solid-gas interface; Surface physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Zeolites: preparations and properties
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/0169-4332(94)90071-X

The interaction of NO with copper in Cu-ZSM-5 and Cu-Y catalysts has been studied by IR techniques and TPSR. The adsorption of CO was followed by DRIFTS. Adsorption of CO on Cu-ZSM-5 and Cu-Y at room temperature gives bands corresponding to chemisorption on Cu + in both cases, with those formed on Cu-ZSM-5 being the more stable in the temperature range up to 473 K. Upon adsorption of NO on Cu-ZSM-5 at room temperature bands corresponding to chemisorption on both Cu +, including those for the dinitrosyl species, and Cu 2+ appear. On Cu-Y only bands belonging to species bound to Cu 2+ are detected. This suggests that the Cu + sites in Cu-Y are rapidly oxidized to Cu 2+ by contact with NO, whereas Cu-ZSM-5 stabilizes Cu + ions. Above 373 K, no NO species were detected on the Cu-Y sample, however with Cu-ZSM-5, bands for the mononitrosyls on both Cu + and Cu 2+ appear at higher temperatures (