Interzeolite transformation and metal encapsulation in the absence of an SDA

Patent metadata

Field	Value
Publication number	US-9938157-B2
Application number	US-201514708833-A
Country	US
Kind code	B2
Filing date	May 11, 2015
Priority date	Jul 23, 2014
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

Provided is a method of encapsulating a metal in a zeolite. The method comprises inserting a metal precursor into a parent zeolite, and then converting the parent zeolite to a zeolite having a higher framework density than the parent zeolite. The conversion is achieved without the need of an organic structure directing agent.

First claim

What is claimed is:

1. Encapsulating a metal in a zeolite by the method of:
(a) inserting a metal or metal precursor into a parent zeolite, and
(b) converting the parent zeolite to a zeolite having a higher framework density than the parent zeolite, in the absence of a structure directing agent (SDA), wherein the conversion is conducted in a basic solution having a NaOH/SiO 2 ratio in the range of from 0.25 to 1.0 and a H 2 O/SiO 2 ratio greater than 50, and at a temperature above the crystallization temperature of the parent zeolite.

2. The method of claim 1 , wherein seed crystals of the higher framework density zeolite are added to the parent zeolite prior to or during the conversion.

3. The method of claim 1 , wherein the conversion is achieved by hydrothermal synthesis.

4. The method of claim 1 , wherein the conversion is achieved in a basic solution.

5. The method of claim 1 , wherein the metal has dimensions such that it cannot be ion-exchanged or impregnated directly into the higher framework density zeolite.

6. The method of claim 5 , wherein the metal is Pt, Rh, Ru or Cu.

7. The method of claim 1 , wherein the parent zeolite is BEA or FAU.

8. The method of claim 1 , wherein the parent zeolite is a Y zeolite.

9. The method of claim 1 , wherein the higher framework density zeolite is ZSM-5, SSZ-35, ZSM-12 or chabazite.

10. The method of claim 1 , wherein the parent zeolite is BEA or FAU, the higher framework density zeolite is ZSM-5, and the metal is Pt, Rh or Ru.

11. The method of claim 1 , wherein the parent zeolite comprises a Y zeolite, the higher framework zeolite is a chabazite, and the metal is Cu.

12. The method of claim 1 , wherein the higher framework density zeolite has a silica/alumina ratio of 10 or greater.

13. The method of claim 12 , wherein the silica/alumina ratio is 25 or greater.

14. The method of claim 1 , wherein the metal precursor comprises an amine complex.

15. The method of claim 1 , wherein the metal precursor is a ligated metal.

16. The method of claim 1 , wherein the metal comprises a metal cluster.

17. The method of claim 1 , wherein the insertion is achieved by exchanging cationic metal precursors and reducing the metal precursors with H 2 to form metal clusters.

Assignees

• Goel Sarika
• Zones Stacey Ian
• Iglesia Enrique
• Chevron Usa Inc
• Univ California

Inventors

• Goel Sarika
• Zones Stacey Ian
• Iglesia Enrique

Classifications

• C01B39/48

  using at least one organic template directing agent · CPC title

• C01B39/40

  using at least one organic template directing agent · CPC title

• B01J29/40

  of the pentasil type, e.g. types ZSM-5, ZSM-8 or ZSM-11, as exemplified by patent documents US3702886, GB1334243 and US3709979, respectively · CPC title

• C01B39/42

  Type ZSM-12 · CPC title

• C01B39/44

  Ferrierite type, e.g. types ZSM-21, ZSM-35 or ZSM-38 · CPC title