| 摘要 |
PURPOSE:To obtain the titled composition capable of being stably used even at a high temp., by containing La2O3 and Al2O3 as main components of a carrier in such a state that at least a part of La2O3 and Al2O3 is present in a lanthanum/ beta-alumina form having a specific composition. CONSTITUTION:In a carrier containing La2O3 and Al2O3 as main components, at least a part of La2O3 and Al2O3 has a lanthanum/beta-alumina form having a composition of La2O3.11-14Al2O3 and, further, the compositional ratio of La2O3 is 2-20mol% and Al2O3 in the carrier is set to a range wherein La2O3 is 2- 20mol% and Al2O3 is 80-98mol% and the sum total amount of La2O3 and Al2O3 is set to 50wt% or more. In addition, the above-mentioned carrier is selected so as to have a specific surface area of at least 10m<2>/g after baking at 1,200 deg.C for 2hr. By allowing the carrier to have a high specific surface area even at a high temp. as mentioned above, said carrier can stably support a catalytically active component in a highly dispersed state and can provide a highly active catalyst. |
