Abstract |
As with any solvent, stabilizing a multivalent element at a given oxidation level in the glass depends on the thermodynamic conditions. The effects of temperature in the oxidation-reduction equilibrium have been previously noted with higher temperatures being conductive to reduced states. 30Ce2O-70P2O5 binary system glasses were prepared. The effects of melting temperature and time on Ce4+ and Ce3+ ion concentration were studied with X-ray photoelectron spectroscopy (XPS). Different melting conditions were investigated at temperatures ranging from 1300 to 1500 ℃ for 60 min, and 1400 ℃ for from 30 min to 90 min. Changes in the catalytic properties of the glasses as a function of Ce4+ and Ce3+ ion concentration were confirmed based on the changes in decomposition starting temperatures using thermogravimetric analysis (TGA). The main changes in the valence states in relation to melting conditions are discussed in terms of the catalytic properties on cerium phosphate glasses. (Received June 10, 2016; Accepted August 23, 2016) |
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Key Words |
glasses, melting condition, Ce oxidation state, catalytic property |
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