EXHAUST GAS-PURIFYING CATALYST
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
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N/A
Issued Date -
N/A
app pub date -
Oct 4, 2013
filing date -
Apr 5, 2007
priority date (Note) -
Abandoned
status (Latency Note)
Importance
Abstract
A high NOx-purifying performance at high temperature conditions is achieved with a small amount of precious metal used. An exhaust gas-purifying catalyst includes a substrate, a lower layer formed on the substrate and including a first composite oxide, palladium and platinum, and an upper layer formed on the lower layer and including a second composite oxide and rhodium. The first composite oxide includes cerium, zirconium, and an element selected from the group consisting of rare-earth elements other than cerium and alkaline-earth elements. A mass ratio of platinum with respect to palladium falls within a range of 1/50 to 1/20. The second composite oxide includes zirconium and an element selected from the group consisting of rare-earth elements other than cerium and alkaline-earth elements and has an atomic ratio of cerium with respect to zirconium smaller than that of the first composite oxide.
First Claim
Other Claims data not available