Coordination and reactivity of Cu/sup 2 +/ Cations in mordenite and ZSM-5
An ESR study has been made of the localization of Cu/sup 2 +/ cations introduced by exchange into the Na and H forms of mordenite and ZSM-5. It has been shown that in the HM with low degrees of exchange, the Cu/sup 2 +/ cations are localized in isolation, having the coordination of a square pyramid, stable when treated in CO at 400/sup 0/. With increasing exchange in the HM, interacting Cu/sup 2 +/ cations appear; these are reduced in CO at 300-400/sup 0/. In ZSM-5, the fraction of interacting Cu/sup 2 +/ ions is insignificant; and for the isolated Cu/sup 2 +/ cations, two types of coordination are characteristic: square pyramid and plane square. Localization in a plane square is also characteristic for part of the isolated Cu/sup 2 +/ cations in CuNaM. The coordination unsaturation of the isolated Cu/sup 2 +/ cations in these zeolites is confirmed by the strong influence of CO and O/sub 2/ on the hfs of the ESR spectra of the Cu/sup 2 +/ ions. Calcination of the CuM and Cu-ZSM-5 specimens in air at 800/sup 0/ does not lead to aggregation of the isolated Cu/sup 2 +/ ions. Vacuum-baking at 450/sup 0/ does not bring about reduction of Cu/sup 2 +/ cations in any of the specimens that were investigated.
- Research Organization:
- N.D. Zelinskii Institute of Organic Chemistry, Acad. of Sci., Moscow
- OSTI ID:
- 6969461
- Journal Information:
- Kinet. Catal. (Engl. Transl.); (United States), Journal Name: Kinet. Catal. (Engl. Transl.); (United States) Vol. 26:2,PT.2; ISSN KICAA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Rearrangement of cationic sites in CuH-ZSM-5 and reactivity loss upon high-temperature calcination and steam aging
Insertion of transition metal ions into cationic sites of high-silica zeolites by reaction in the solid phase. I. Topochemical reaction of copper compounds with mordenite and pentasils
Related Subjects
360101* -- Metals & Alloys-- Preparation & Fabrication
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ACTIVATION ENERGY
CALCINATION
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COORDINATION VALENCES
COPPER COMPOUNDS
DECOMPOSITION
ELECTRON SPIN RESONANCE
ELEMENTS
ENERGY
HEAT TREATMENTS
HYPERFINE STRUCTURE
INORGANIC ION EXCHANGERS
ION EXCHANGE
ION EXCHANGE MATERIALS
ION IMPLANTATION
MAGNETIC RESONANCE
MATERIALS
MINERALS
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PYROLYSIS
RESONANCE
SYNTHESIS
TEMPERATURE EFFECTS
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
VALENCE
ZEOLITES