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. 14, 2000
Filed:
Jul. 14, 1998
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
The present invention relates to an alloy catalyst for purifying an exhaust gas, and particularly provides an alloy catalyst excellent in nitrogen oxide purification characteristics in the lean region by improving the catalytic activity by coating first catalytic metal particles with a second metal coagulated phase, and a process for producing the same, the alloy catalyst for purifying an exhaust gas having a structure in which metal coagulated phases being applied to and supported by a metal oxide, and comprising first catalytic metal particles having an average particle size of up to 30 nm, and a second metal coagulated phase containing at least one metal, differing from the catalytic metal particles, and applying to the first catalytic metal particles at a coating ratio of at least 45%, and the process for producing an alloy catalyst for purifying an exhaust gas, comprising the steps of allowing first catalytic metal particles having an average particle size of up to 30 nm to adhere onto a metal oxide, and reduction precipitating a second metal coagulated phase containing at least one metal differing from the first catalytic metal particles thereon, and comprising at least one metal selected from the group consisting of Pt, Pd, Au, Rh, Ag and Ir.