| abstract |
[PROBLEMS] To provide an oxygen storage substance which has higher oxygen storage capacity than conventional substances and is inexpensive. [MEANS FOR SOLVING PROBLEMS] The oxygen storage substance is a calcium aluminosilicate (mayenite), i.e., a substance of a crystal structure which is synthesized by hydrothermally treating a mixture of calcium oxide, alumina (sol), and amorphous silica, has a three-dimensional network composed of AlO4 tetrahedrons and (Al,Si)O4 tetrahedrons in which part of the aluminum atoms have been replaced with silicon atoms, with vertex oxygen atoms being shared, and has oxide ions (O2-) occluded in microspaces in the structure. Part of the calcium atoms may be replaced with atoms of a transition metal, e.g., copper. |