GOLD AND IRON SUPPORTED ON Y-TYPE ZEOLITE FOR CARBON-MONOXIDE OXIDATION

Gold and iron supported on Y-type zeolite for carbon monoxide oxidatio n have been studied. They were prepared by ion exchange of gold(III) c ompounds with Y-type zeolite, iron-impregnated Y-type zeolite, or iron -exchanged Y-type zeolite in a chloroauric acid solution. The as-prepa red gold/Y sample possessed high activity for carbon monoxide oxidatio n, but it gradually and irreversibly deactivated during the reaction. The deactivation was attributed to the transformation of some gold ion s to gold metal. The activities of as-prepared gold/iron/Y samples wer e poor when compared with that of gold/Y, but their activities were ma rkedly promoted by a high-temperature reduction treatment at 570 degre es C. This is ascribed to the fact that the reduced gold/iron/Y cataly st could catch and release oxygen at low temperature.