| 摘要 |
<P>PROBLEM TO BE SOLVED: To control the particle growth of a noble metal and to improve methane purification activity while improving OSC (oxygen absorption and release capacity). <P>SOLUTION: On at least the Al<SB>2</SB>O<SB>3</SB>layer 2 of a composite particle comprising Ce<SB>2</SB>-ZrO<SB>2</SB>solid solution particle 1 and the Al<SB>2</SB>O<SB>3</SB>layer 2 covering at least a part of the surface of the solid solution particle 1, Pt and Pd are supported. The gain growth of the noble metals supported on the Al<SB>2</SB>O<SB>3</SB>layer 2 is controlled, the noble metals exist as fine particles even after endurance, and lots of active points exist on the surface. Since the Al<SB>2</SB>O<SB>3</SB>layer 2 is thin, it is oxygen-permeable, and OSC by the supported Pt, Pd, and the solid solution particle 1 is exhibited. Moreover, since Pd is highly dispersed and supported, methane purification activity is also improved. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
