Method of making AFX zeolites having high thermal stability
US11904303B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 2019 |
| Grant date | Feb 20, 2024 |
| Priority date | — |
| Expiry date | Mar 25, 2040 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF01N2370/04
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method of forming an AFX zeolite in a hydrothermal synthesis that exhibits a silica to alumina (SiO2AI2O3) molar ratio (SAR) that is between 8:1 and 26:1; has a morphology that includes one or more of cubic, spheroidal, or rhombic particles with a crystal size that is in the range of about 0.1 micrometer (μm) to 10 μm. This AFX zeolite also exhibits a Brönsted acidity that is in the range of 1.2 mmol/g to 3.6 mmol/g as measured by ammonia temperature programmed desorption. A catalyst formed by substituting a metal into the framework of the zeolite exhibits about a 100% conversion of NO emissions over the temperature range of 300° C. to 650° C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.