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:
Nov. 05, 1991
Filed:
Jul. 06, 1990
Hiroshi Murakami, Hiroshima, JP;
Kazuko Yamagata, Hiroshima, JP;
Mazda Motor Corporation, Hiroshima, JP;
Abstract
A catalyst for the purification of exhaust gases contains a catalyst carrier with a first coat layer formed on a surface of the catalyst carrier and with a second coat layer formed on a surface of the first coat layer. The first coat layer contains an active alumina and a catalyst component comprised of a noble metal such as platinum and rhodium and at least one of zirconium oxide, lanthanum oxide and barium oxide is immobilized on particles of the active alumina, and the second coat layer contains an active alumina, cerium oxide and a catalyst component comprised of another noble metal such as palladium. The oxides of zirconium, lanthanum and/or barium can prevent the alumina particles from aggregating together due to heat, thereby improving heat resistance of the catalyst.