EXHAUST EMISSION CONTROL DEVICE AND ITS PROCESS OF MANUFACTURE

文件类型：PDF文档
文件大小：253K
PROBLEM TO BE SOLVED : To keep a catalytic activity of rhodium at a high state by preventing sintering. SOLUTION : This invention relates to an exhaust emission control device having an upper layer and a lower layer. The upper layer has a first catalyst (10) for exhaust emission control containing first carrier particles (1), second carrier particles (2) and noble metal catalyst particles (3) held by these carrier particles. The first carrier particles (1) contain at least one kind of metal oxide of a group of silica, alumina, ceria, zirconia and titania and rare earth oxide other than ceria. The second carrier particles (2) contain rare earth oxide other than ceria. A content of the metal oxide of the first carrier particles (1) is higher than a content of the metal oxide of the second carrier particles (2), a content of rare earth oxide of the second carrier particles (2) is higher than a content of the rare earth oxide of the first carrier particles (1) and the noble metal catalyst particles (3) include rhodium particles. SELECTED DRAWING : Figure 1 COPYRIGHT : (C)2018, JPO&INPIT