The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 09, 1984
Filed:
Jan. 26, 1983
Gwan Kim, Olney, MD (US);
Michael V Ernest, Catonsville, MD (US);
W. R. Grace & Co., New York, NY (US);
Abstract
Catalysts are made from supports which are doubly promoted with ceria and an alkali metal oxide by adding these promoters and the catalytic noble metal components in a specified order. The ceria is first applied to the support. It can be applied in a salt form such as cerous nitrate. This impregnated support is then calcined to form a deposit of ceria. Next, solutions bearing the noble metals are applied to the ceria-promoted support and with these solutions the alkali metal component is applied. After subsequent elevated temperature activation, the alkali metal component is converted to an alkali metal oxide and the noble metals are converted into their metallic or oxide form. When lithium is chosen as the alkali metal promoter, it can alternatively be applied to the support along with the initial ceria promoter. After calcining the support to yield the ceria and lithia promoters, the noble metals can then be deposited and subsequently activated at an elevated temperature. Using this process it is possible to have the noble metals deposited on the support so that their penetration depth is less than 300 microns as measured by the SnCl.sub.2 solution staining method to provide an effective three-way catalyst suitable for use in auto emission control.