Nanocrystal-sized cerium-zirconium oxide material and method of making the same
US12129182B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 2021 |
| Grant date | Oct 29, 2024 |
| Priority date | — |
| Expiry date | Jun 6, 2043 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02T10/12
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A nanocrystal-sized cerium-zirconium mixed oxide material includes at least 30% by mass zirconium oxide; between 5% to 55% by mass cerium oxide; and a total of 25% or less by mass of at least one oxide of a rare earth metal selected from the group of lanthanum, neodymium, praseodymium, or yttrium. The nanocrystal-sized cerium-zirconium mixed oxide exhibits hierarchically ordered aggregates having a d50 particle size less than 1.5 μm and a total pore volume after calcination at a temperature of 600° C. or more that is at least 0.7 cm3/g with a fraction of pores between 2 nm to 10 nm being less than 15%. The nanocrystal-sized cerium-zirconium mixed oxide material is prepared using a co-precipitation method followed by milling the dried and calcined oxide material. The nanocrystal-sized cerium-zirconium mixed oxide material forms a particulate filter that may be used in an exhaust system arising from a gas or diesel engine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.