Sidley & Austin
Catalyst for purifying exhaust gas
 A catalyst has a base catalyst layer containing platinum and barium as precious metal supported by alumina and an over catalyst layer containing platinum and rhodium as precious metal supported by zeolitr. The platinum and rhodium in the over catalyst layer activate NOx and HC so as to make them more reactive in terms of energy, and the barium in the base catalyst layer makes the platinum be more dispersive in the base catalyst layer. Under the existence of dispersive platinum, NOx in exhaust gas is decomposed and purified by reaction with reactive NO.sub.2 and partially oxidized HC generated in the over catalyst layer. 
Mazda Motor Corporation
F B B Y F B F Y
F01N B01J B01J Y02A F01N B01D F01N Y02T
additional inventional inventional additional additional inventional inventional additional
Takahiro Kenji Hiroshi Makoto Hideharu Akihide
Kurokawa Okamoto Yamada Kyogoku Iwakuni Takami