초록 ▼

A catalyst, which is capable of controlling not only HC, CO and NOx, but also H2S emission from the tail pipe of catalytic converter-equipped automobiles, is made of noble metals promoted with ceria-rich rare earth oxides, preferably doubly promoted along with alkali metal oxides, and oxides of nick

A catalyst, which is capable of controlling not only HC, CO and NOx, but also H2S emission from the tail pipe of catalytic converter-equipped automobiles, is made of noble metals promoted with ceria-rich rare earth oxides, preferably doubly promoted along with alkali metal oxides, and oxides of nickel and/or iron as an H2S gettering ingredient. The oxides of nickel and/or iron are present in an H2S gettering effective amount and in an amount up to 10 wt %. The alumina support can have additionally from 0 to 20% SiO2 present.

대표청구항 ▼

In a catalyst suitable for use as a catalyst for auto emission control characterized by an alumina support with components deposited thereon consisting essentially of lanthana as a stabilizer in an amount of about 1 to 10% by weight expressed as La2O3 which is either in the form of lanthana only or

In a catalyst suitable for use as a catalyst for auto emission control characterized by an alumina support with components deposited thereon consisting essentially of lanthana as a stabilizer in an amount of about 1 to 10% by weight expressed as La2O3 which is either in the form of lanthana only or in the form of lanthana-rich rare earth oxides where the La2O3 is at least 50% by weight of the total rare earth oxides, 1-20% by weight of ceria as a promoter, at least 0.5 to about 5% by weight of an alkali metal oxide as a promoter, and a catalytically-effective amount of one or more platinum group metals, the improvement comprising adding H2S gettering capability by having the catalyst further comprise (a) an H2S gettering metal oxide selected from the group consisting of oxides of Ni, Fe and mixtures thereof in an amount from an H2S gettering effective amount up to 10 weight %, provided that when the H2S gettering metal oxide is just NiO, the maximum concentration of the NiO in the first 300 micron layer is at least about twice its average concentration throughout the support; and (b) wherein said alumina support can have additionally from 0 to 20% SiO2 present.