Methods for exhaust gas purification
US11607672B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jul 11, 2022 |
| Grant date | Mar 21, 2023 |
| Priority date | — |
| Expiry date | Jul 11, 2042 |
Classification
- Technology area (CPC —)General
Abstract
Methods for exhaust gas purification, including the steps of: attaching an exhaust gas purification catalyst to an exhaust system of an internal combustion engine, and supplying an exhaust gas to the exhaust gas purification catalyst, where the exhaust gas purification catalyst includes an upper layer containing first carrier particles which are particles of an inorganic oxide and rhodium, and a lower layer containing second carrier particles which are particles of an inorganic oxide, the upper layer includes a rhodium-rich portion near the surface of the upper layer on the upstream side of the exhaust gas flow, and the existence range of the rhodium-rich portion is in a range of greater than 50% to 80% of the length of the upper layer from a downstream side end of an exhaust gas flow and of less than 20 μm in the depth direction from an outermost surface of the upper layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.