β-Zeolite for SCR catalyst and method for purifying nitrogen oxides using same
US9061241B2 · kind B2 · utility
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Key dates
| Filing date | Mar 14, 2007 |
| Grant date | Jun 23, 2015 |
| Priority date | — |
| Expiry date | Jul 6, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2982
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An SCR catalyst using a β-zeolite in which the molar ratio of SiO2/Al2O3 is from 20 to less than 40, the particle diameter determined by SEM is 0.35 μm or more, the full width at half maximum (FWHM) of the X-ray diffraction peak for (302) is less than 0.30°, and the amount of adsorbed NH3 is 1 mmol/g or more, or has an amount of adsorbed NH3 following hydrothermal aging of 0.4 mmol/g or more, demonstrates high catalytic activity for NOx reduction at low temperatures following hydrothermal aging while also demonstrating a low level of discharge of irritating ammonia in exhaust gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.