Process for preparing iron(III)-exchanged zeolite composition

US10710059B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Qi Fu · Shanghai, CN
• Barbara Slawski · North Royalton, US
• Peter Pfab · Schwarzheide, DE

Key dates

• Filing date: Dec 20, 2016
• Grant date: Jul 14, 2020
• Expiry date: Dec 20, 2036

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02T10/12
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The present disclosure relates to processes for formation of a molecular sieve, particularly a metal-promoted molecular sieve, and more particularly an Iron(III) exchanged zeolite. Preferably, the zeolite is of the chabazite form or similar structure. The processes can include combining a zeolite with Iron(III) cations in an aqueous medium. The process can be carried out at a pH of less than about 7, and a buffering material can be used with the aqueous medium. The processes beneficially result in Iron exchange that can approach 100% along with removal of cations (such as sodium, NH4, and H) from the zeolite. An Iron(III)-exchanged zeolite prepared according to the disclosed processes can include about 2,000 ppm or less of cation and about 1% by weight or greater of Iron(III). The disclosure also provides catalysts (e.g., SCR catalysts) and exhaust treatment systems including the Iron(III)-exchanged zeolite.