Formation of Cu-MFI NO Decomposition Catalyst via Reductive Solid-State Ion Exchange

• Published in: Journal of physical chemistry (1952) Vol. 99; no. 3; pp. 864 - 868
• Main Authors: Price, Geoffrey L, Kanazirev, Vladislav, Church, Daniel F
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 1995
• Subjects: 400102 - Chemical & Spectral Procedures; 400201 - Chemical & Physicochemical Properties; CATALYSTS; CHALCOGENIDES; CHEMICAL REACTIONS; COPPER COMPOUNDS; DECOMPOSITION; ELECTRON SPIN RESONANCE; HEAT TREATMENTS; INORGANIC ION EXCHANGERS; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ION EXCHANGE; ION EXCHANGE MATERIALS; MAGNETIC RESONANCE; MATERIALS; MINERALS; NITRIC OXIDE; NITROGEN COMPOUNDS; NITROGEN OXIDES; OXIDES; OXYGEN COMPOUNDS; REDUCTION; RESONANCE; SILICATE MINERALS; SYNTHESIS; TRANSITION ELEMENT COMPOUNDS; ZEOLITES
• ISSN: 0022-3654; 1541-5740
• DOI: 10.1021/j100003a004

High-temperature treatment of a mechanical mixture of CuO and H-MFI zeolite in the absence of O[sub 2] produced a Cu ion-exchanged zeolite catalyst with a high activity for the catalytic decomposition of NO to N[sub 2] and O[sub 2]. Cu is probably introduced as Cu[sup +] cations in zeolite ion-exchange sites via a solid-state ion-exchange process which includes CuO autoreduction to Cu[sup +]. ESR, 1-propanamine thermal desorption, and TPR characterization are consistent with this model. This preparation technique has a theoretical exchange limit of 1 Cu/framework Al, which is double the limit theoretically imposed on Cu[sup 2+] exchange. The preferred preparation conditions give rise to a material which approaches this theoretical limit, and there are probably similarities between catalysts prepared by this method and [open quotes]overexchanged[close quotes] Cu[sup 2+]-MFI materials often reported for NO decomposition. 30 refs., 4 figs.