Bi-metal molecular sieve catalysts

Patent metadata

Field	Value
Publication number	US-2016243533-A1
Application number	US-201615047879-A
Country	US
Kind code	A1
Filing date	Feb 19, 2016
Priority date	Feb 20, 2015
Publication date	Aug 25, 2016
Grant date	—

Abstract

Provided is a catalyst composition comprising a small pore molecular sieve, about 0.5-5 weight percent of a transition metal (T M ) selected from copper and/or iron, based on the total weight of the zeolite, and about 0.5-5 weight percent nickel, based on the total weight of the molecular sieve, wherein the transition metal and nickel are present in a T M :Ni ratio of about 10:1 to about 1:2. Also provided is a synthesis method for preparing a small pore molecular sieve having both Cu and Ni incorporated in situ. Also provided is a method for using such a catalyst for selectively reducing NOx in an exhaust gas.

First claim

What is claimed is:

1 . A catalyst composition comprising a small pore molecular sieve, about 0.5-5 weight percent of a transition metal (T M ) selected from copper and/or iron, based on the total weight of the molecular sieve, and about 0.5-5 weight percent nickel, based on the total weight of the molecular sieve, wherein the transition metal and nickel are present in a T M :Ni ratio of about 10:1 to about 1:2.

2 . The catalyst composition of claim 1 , wherein the transition metal and the nickel are incorporated into the molecular sieve during synthesis.

3 . The catalyst composition of claim 1 , wherein a majority of the transition metal and the nickel are present as extra-framework metals.

4 . The catalyst composition of claim 1 , wherein the molecular sieve is composed of crystals, and the transition metal and the nickel are present in a weight percentage as measured by XPS that is within 10% of their weight percentage as measured by XRF

5 . The catalyst composition of claim 1 , wherein the molecular sieve has a CHA framework.

6 . The catalyst composition of claim 1 , wherein the molecular sieve has an AEI framework.

7 . The catalyst composition of claim 1 , wherein the molecular sieve is a zeolite having a silica-to-alumina ratio of about 10 to about 50.

8 . The catalyst composition of claim 1 , wherein the molecular sieve is essentially free of non-aluminum framework metals.

9 . The catalyst composition of claim 1 , wherein the molecular sieve has a mean crystal size of about 0.5 to 5 microns.

10 . The catalyst composition of claim 1 , wherein the molecular sieve is essentially free of any post-synthesis exchanged metal.

11 . A method for synthesizing a molecular sieve comprising:
heating an admixture comprising a source of silica, a source of alumia, optionally a source of phosphate, a source of copper and/or iron, a source of nickel, and at least one structure directing agent to form zeolite crystals containing nickel and at least one of copper and iron, and separating the molecular sieve crystals from the mother liquor.

12 . The method of claim 11 , wherein the copper and/or iron and the nickel are separately in the form of a metal salt when added to the admixture.

13 . The method of claim 11 , wherein the copper and/or iron and the nickel are separately in the form of a metallo-organic complex comprising at least one organic constituent selected from diethylenetriamine (DETA); N-(2-hydroxyethyl)ethylenediamine (HEEDA); triethylenetetramine (TETA); N,N′-bis(2-aminoethyl)-1,3-propanediamine (232); 1,2-bis(3-aminopropylamino)ethane (323); tetraethylenepentamine (TEPA); pentaethylenehexamine (PEHA); Tetraammine; and bipyridine.

14 . A catalyst article comprising a substrate coated with a catalyst composition according to claim 1 .

15 . The catalyst article of claim 14 , wherein the substrate is a metal flow-through substrate, a honeycomb flow-through substrate, a honeycomb wall-flow filter, or a honeycomb partial filter.

16 . The catalyst article of claim 15 , further comprising a second coating comprising an oxidation catalyst.

17 . The catalyst composition of claim 1 , and wherein the catalyst is an SCR catalyst and is effective for reducing NOx to N2 in the presence of a reductant.

18 . A method for treating an exhaust gas comprising contacting a gas comprising NOx and a reductant with a catalyst according to claim 1 to catalytically reduce at least a portion of the NOx to N2.

19 . The method of claim 18 , wherein the exhaust gas further comprises a source of sulfur.

20 . The method of claim 18 , wherein the exhaust gas comprises at least 10 ppm sulfur.

Assignees

• Johnson Matthey Plc

Inventors

• Rivas-Cardona Alejandra
• Chen Hai-Ying
• Fedeyko Joseph Michael

Classifications

• Y02T10/12

  Improving ICE efficiencies · CPC title

• B01D2255/20761

  Copper · CPC title

• Y02P20/584

  Recycling of catalysts · CPC title

• B01D2255/50

  Zeolites · CPC title

• B01J37/0246

  Coatings comprising a zeolite · CPC title