| 摘要 |
<p>PURPOSE: To obtain a three-way catalyst having high activity for automobiles by first depositing discontinuous lanthanum oxide on an alumina supporting body, then depositing precious metals of palladium and rhodium, and then depositing titania. CONSTITUTION: First, a supporting body substantially comprising alumina is coated with discontinuous lanthanum oxide. Then a precious metal catalyst comprising palladium and rhodium, in which contains rhodium is present <=10% of palladium and palladium is present by >=60 wt.% of the precious metal catalyst, is discontinuously deposited on the supporting body. Further, a nonprecious catalyst comprising titanium oxide is discontinuously deposited on or around the noble metal catalyst and lanthanum. Thereby, by combining the palladium and rhodium of the precious metal catalyst and lanthanum oxide and titania of the non-precious metal catalyst, the obtd. three-way catalyst for automotive emission control has high activity.</p> |
