Anionic PGM carboxylate assisted PGM nanoparticle synthesis for exhaust gas treatment applications

Patent metadata

Field	Value
Publication number	US-12544738-B2
Application number	US-202217811602-A
Country	US
Kind code	B2
Filing date	Jul 11, 2022
Priority date	Jul 12, 2021
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

A method of manufacturing a catalyst article, the method comprising: providing an anionic complex comprising a PGM and a carboxylate ion; providing a support material; applying the anionic complex to the support material to form a loaded support material; disposing the loaded support material on a substrate; and heating the loaded support material to form nanoparticles of the PGM on the support material.

First claim

The invention claimed is:

1 . A method of manufacturing a catalyst article, the method comprising:
providing a PGM hydroxide and/or a water-insoluble PGM salt; contacting the PGM hydroxide and/or water-insoluble PGM salt with an aqueous carboxylic acid solution; and optionally recovering an anionic complex in the form of an aqueous solution comprising an anionic complex comprising a PGM and a carboxylate ion, wherein the carboxylate ion comprises a hydroxyl group; providing a support material; applying the anionic complex to the support material to form a loaded support material; disposing the loaded support material on a substrate; and heating the loaded support material to form nanoparticles of the PGM on the support material.

2 . The method of claim 1 , wherein the PGM of the PGM hydroxide is rhodium and/or platinum, and/or the PGM of the water-insoluble PGM salt.

3 . The method of claim 1 , wherein the substrate is in the form of a honeycomb monolith, a wall flow filter or a flow through filter.

4 . A catalyst article obtainable by the method of claim 1 , the catalyst article for use in an emission treatment system.

5 . The catalyst article of claim 4 for three-way catalysis, diesel oxidation catalysis, or NOx trap catalysis.

6 . An emission treatment system comprising the catalyst article of claim 4 .

7 . The emission treatment system of claim 6 for a gasoline engine.

8 . A method of treating an exhaust gas, the method comprising:
providing the catalyst article of claim 4 ; and contacting the catalyst article with an exhaust gas.

9 . The method of claim 1 , wherein the carboxylate ion comprises two or more carboxyl functional groups.

10 . The method of claim 1 , wherein the carboxylate ion comprises from 2 to 6 carbon atoms.

11 . The method of claim 1 , wherein the carboxylate ion comprises an alpha-hydroxy acid functional group.

12 . The method of claim 1 , wherein the carboxylate ion comprises one or more of citrate, malate, tartrate, tartronate, lactate and glycolate.

13 . The method of claim 1 , wherein the carboxylate ion comprises citrate.

14 . The method of claim 1 , wherein the PGM is selected from one or more of rhodium, palladium, platinum and ruthenium.

15 . The method of claim 14 , wherein the PGM comprises rhodium, palladium, platinum or a combination thereof, preferably rhodium and/or palladium.

16 . The method of claim 1 , wherein the anionic complex comprises one or more of Pt (IV) malonate, Pt (IV) succinate, Pt (II, IV) oxalate, Pd (II) citrate, Pd (II) lactate, Pd (II) oxalate, Pd (II) glycolate, Pd (II) malate, Rh (II) citrate, Rh (III) citrate, Rh (II) lactate, Rh (III) lactate and Ru (III) oxalate.

17 . The method of claim 1 , wherein the anionic complex is provided in the form of an aqueous solution comprising the anionic complex.

18 . The method of claim 17 , wherein the aqueous solution does not comprise a PGM nitrate.

19 . The method of claim 1 , wherein the support material comprises one of more of Al 2 O 3 , TiO 2 , CeO 2 , ZrO 2 , CeO 2 —ZrO 2 , V 2 O 5 , La 2 O 3 and zeolites.

Assignees

• Johnson Matthey Plc
• Johnson Matthey Shanghai Chemicals Ltd

Inventors

• Blum Jochem Alex
• Chang Hsiao-Lan
• Chen Hai-Ying
• Collis Nicola
• Gabrielsson Jennifer Marion
• Moxham Gemma Louisa
• Muresan Nicoleta
• Qiao Dongsheng
• Schofield Emma
• Thompsett David
• Wan Yaping

Classifications

• B01J35/45

  Nanoparticles · CPC title

• B01J35/56

  Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional [3D] monoliths · CPC title

• F01N2370/04

  Zeolitic material · CPC title

• F01N3/2842

  specially adapted for monolithic supports, e.g. of honeycomb type (F01N3/2853 - F01N3/2871 take precedence) · CPC title

• F01N3/2803

  characterised by structure, by material or by manufacturing of catalyst support · CPC title