High specific surface/reducibility catalyst/catalyst support compositions comprising oxides of zirconium, cerium and lanthanum and of yttrium, gadolinium or samarium

摘要

Catalyst/catalyst support composition essentially consist of oxides of zirconium, cerium and lanthanum and of another rare earth selected from among yttrium, gadolinium and samarium, having a proportion of the lanthanum oxide and the oxide of the other rare earth of at least 15% and specific surfaces of at least 40 m²/g and at least 15 m²/g after calcination respectively for 4 hours at 1,000° C. and 10 hours at 1,150° C.; after calcination for 10 hours at 1,200° C. these have a surface of at least 7 m²/g and such surface is at least 5 m²/g for an embodiment in which after 10 hours of calcination at 1,150° C. the composition is in the form of a pure solid solution.