12CaO 7Al2O3 COMPOUND AND METHOD FOR PREPARATION THEREOF

There is provided a C12A7 compound capable of selectively and reversibly clathrating X ions, such as active oxygen radicals, with improved controllability. The C12A7 compound clathrating OH ions and On at a concentration of 2 x 10 cm or less can be prepared by subjecting a mixed material containing Ca and Al to a solid phase reaction at a firing temperature not lower than 1200 DEG C and lower than 1449 DEG C in a dry oxygen atmosphere having an oxygen partial pressure of 0.1 atm or more and a water vapor partial pressure of 10 atm or less, keeping the resultant product at a temperature of 1200 DEG C or higher, and cooling rapidly. The C12A7 compound is heat-treated to clathrate OH ions at a concentration of 2 x 10 cm or less, and On at a high concentration of more than 2 x 10 cm. The compound can reversibly clathrate or release On ion radicals through the elevation or lowering of the temperature thereof in a temperature range of 300 to 850 DEG C. The compound is useful for an oxidation catalyst, an anti-bacterial agent, an ion conducting material, an electrode for a solid-electrolyte fuel cell, and the like.