Framework chemistry and structure involving electron transfer and europium in zeolites

Conference · Thu Dec 01 04:00:00 EST 1983

OSTI ID:5335217

Stucky, G D; Iton, L; Morrison, T; Shenoy, G; Suib, S; Zerger, R P

The relationship between the zeolite framework and the coordination number and electron transfer properties of Eu/sup 2 +/ and Eu/sup 3 +/ have been investigated by time-resolved luminescence (TRL) EXAFS, EPR, and Moessbauer spectroscopy. TRL determined lifetimes are sensitive to non-framework oxygen atoms and can be used to help distinguish between coordination involving OH groups and the framework oxygen atoms. The suitability and some of the present limitations of this application of TRL, which is new to the study of zeolites, are described. The average coordination of hydrated Eu/sup 3 +/ in the large-pore zeolite Y is identical to that in aqueous solution, while the coordination number in zeolites A and ZSM-5 is smaller, with framework oxygen atoms displacing water from the Eu/sup 3 +/ coordination sites. Europium metal dissolved in liquid ammonia can be used to generate Eu(NH/sub 3/)/sub 6//sup 2 +/ and solvated electrons. With zeolite X, this solutoin results in the formation of Na/sub 4//sup 3 +/ and two kinds of defects. These are assigned to an electron trapped in an oxygen vacancy arising from a Lewis acid site and a V-type hole center in which the unpaired electron resides on a non-bridging oxygen atom bonded to silicon.

• Research Organization: Du Pont de Nemours (E.I.) and Co., Newark, DE (USA). Central Research and Development Dept.; Argonne National Lab., IL (USA); Connecticut Univ., Storrs (USA). Dept. of Chemistry; McPherson Coll., KS (USA). Dept. of Physical Science
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5335217
• Report Number(s): CONF-8310251-1; ON: DE84006324
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ADSORPTION
AMMONIA
COORDINATION NUMBER
ELECTRON SPIN RESONANCE
ELECTRON TRANSFER
EUROPIUM COMPOUNDS
HYDRATION
HYDRIDES
HYDROGEN COMPOUNDS
INORGANIC ION EXCHANGERS
ION EXCHANGE
ION EXCHANGE MATERIALS
LUMINESCENCE
MAGNETIC RESONANCE
MATERIALS
MINERALS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
RARE EARTH COMPOUNDS
RESONANCE
SOLVATION
SORPTION
SORPTIVE PROPERTIES
STRUCTURAL CHEMICAL ANALYSIS
SURFACE PROPERTIES
ZEOLITES