# US 11,439,992 B2 · Process for preparing iron(III)-exchanged zeolite composition

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- Number: US 11,439,992 B2
- Document ID: US11439992B2
- Status: Granted
- Kind: B2
- Application number: 16/899,138
- Filed: 2020-06-11
- Published: 2020-09-24
- Granted: 2022-09-13
- Earliest claimed: 2015-12-22
- Assignees: BASF SE
- Applicants: BASF Corporation
- Inventors: Qi Fu; Barbara Slawski; Peter Pfab
- Web page: https://patentgrep.com/patent/US11439992B2

## CPC

- B01J 29/723: {CHA-type, e.g. Chabazite, LZ-218}
- B01D 53/9418: {for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas}
- B01J 29/072: Iron group metals or copper
- B01J 29/14: Iron group metals or copper
- B01J 29/76: Iron group metals or copper
- B01J 29/763: {CHA-type, e.g. Chabazite, LZ-218}
- B01J 37/0246: {Coatings comprising a zeolite}
- B01J 37/30: Ion-exchange
- C01B 39/026: {After-treatment}
- F01N 3/106: {Auxiliary oxidation catalysts}
- F01N 3/2066: {Selective catalytic reduction [SCR]}
- B01D 2255/20738: Iron
- B01D 2255/50: Zeolites
- B01J 2229/18: to introduce other elements into or onto the molecular sieve itself
- B01J 2229/186: not in framework positions
- F01N 2370/04: Zeolitic material
- Y02T 10/12: Improving ICE efficiencies
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## 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.

## Claims

### Claim 1

An Iron(III)-exchanged molecular sieve comprising a porous zeolite having a double 6-ring (D6R) building unit structure, wherein cations in the zeolite have been exchanged with Iron(III) cations such that the zeolite includes about 1% by weight of the zeolite or greater of Iron(III), wherein the Iron(III)-exchanged molecular sieve is prepared by combining a zeolite with Iron(III) cations in an aqueous media such that the Iron(III) cations are exchanged into or onto the zeolite to form the Iron(III)-exchanged zeolite, and wherein the aqueous medium comprises a buffering agent and is at a pH of about 2.0 to about 6.0.

### Claim 2 (depends on 1)

The Iron(III)-exchanged molecular sieve of claim 1, wherein the zeolite is a sodium-containing zeolite, an NH4-containing zeolite, or an H-containing zeolite.

### Claim 3 (depends on 1)

The Iron(III)-exchanged molecular sieve of claim 1, wherein the zeolite includes about 1% to about 10% by weight of the zeolite of Iron(III).

### Claim 4 (depends on 1)

The Iron(III)-exchanged molecular sieve of claim 1, wherein the zeolite has a chabazite (CHA) structure.

### Claim 5 (depends on 1)

The Iron(III)-exchanged molecular sieve of claim 1, wherein the zeolite includes sulfate in an amount of about 400 ppm or greater based on the total weight of the Iron(III)-exchanged zeolite.

### Claim 6 (depends on 1)

The Iron(III)-exchanged molecular sieve of claim 1, wherein the Iron(III) is dispersed on the zeolite.

### Claim 7 (depends on 1)

The Iron(III)-exchanged molecular sieve of claim 1, wherein the Iron(III) cations are exchanged onto the zeolite.

### Claim 8 (depends on 1)

A catalyst comprising an Iron(III)-exchanged molecular sieve according to claim 1 combined with a substrate.

### Claim 9 (depends on 1)

A catalyst comprising an Iron(III)-exchanged zeolite according to claim 1.

### Claim 10 (depends on 1)

An exhaust treatment system comprising a selective catalytic reduction (SCR)catalyst positioned to receive an exhaust gas stream, the SCR catalyst including an Iron(III)-exchanged zeolite according to claim 1.

### Claim 11 (depends on 10)

The exhaust treatment system of claim 10, further comprising one or both of a diesel oxidation catalyst (DOC) and a catalyzed soot filter (CSF).

### Claim 12 (depends on 10)

The exhaust treatment system of claim 10, further comprising a reductant injector.