Structured catalyst for oxidation for exhaust gas purification, method for producing same, automobile exhaust gas treatment device, catalytic molding, and gas purification method

Patent metadata

Field	Value
Publication number	US-2020114339-A1
Application number	US-201916698602-A
Country	US
Kind code	A1
Filing date	Nov 27, 2019
Priority date	May 31, 2017
Publication date	Apr 16, 2020
Grant date	—

Abstract

The structured catalyst for oxidation for exhaust gas purification includes a support having a porous structure constituted by a zeolite-type compound, and at least one type of oxidation catalyst that is present in the support and selected from the group consisting of metal and metal oxide, the support having channels that communicate with each other, and the oxidation catalyst being present in at least the channels of the support.

First claim

What is claimed is:

1 . A structured catalyst for oxidation for exhaust gas purification, comprising:
a support of a porous structure composed of a zeolite-type compound; and at least one oxidation catalyst present in the support and selected from the group consisting of metals and metal oxides, wherein the support has channels that communicate with each other, and the oxidation catalyst is present at least in the channels of the support, wherein the metal oxides contain at least one perovskite-type oxide, the channels have any one of a one-dimensional pore, a two-dimensional pore, and a three-dimensional pore defined by a framework of the zeolite-type compound and an enlarged pore portion that is different from any of the one-dimensional pore, the two-dimensional pore, and the three-dimensional pore, and the oxidation catalyst is present at least in the enlarged pore portion.

2 . The structured catalyst for oxidation for exhaust gas purification according to claim 1 , wherein the enlarged pore portion causes a plurality of pores constituting any one of the one-dimensional pore, the two-dimensional pore, and the three-dimensional pore to communicate with each other.

3 . The structured catalyst for oxidation for exhaust gas purification according to claim 1 , wherein
the oxidation catalyst is made of at least one type of oxidation catalytic nanoparticles selected from the group consisting of metal nanoparticles and metal oxide nanoparticles, and an average particle size of the oxidation catalytic nanoparticles is greater than an average inner diameter of the channels and is less than or equal to an inner diameter of the enlarged pore portion.

4 . The structured catalyst for oxidation for exhaust gas purification according to claim 3 , wherein the oxidation catalytic nanoparticles are made of at least one type of metal selected from the group consisting of cobalt, iron, copper, silver, manganese, nickel, chromium, tin, zinc, titanium, and platinum, and oxides of the metals.

5 . The structured catalyst for oxidation for exhaust gas purification according to claim 3 , wherein the content of the metal element (M) of the oxidation catalytic nanoparticles is from 0.5 to 2.5 mass % with respect to the oxidation catalyst.

6 . The structured catalyst for oxidation for exhaust gas purification according to claim 3 , wherein an average particle size of the metal oxide nanoparticles is from 0.1 nm to 50 nm.

7 . The structured catalyst for oxidation for exhaust gas purification according to claim 3 , wherein the ratio of the average particle size of the metal oxide nanoparticles to the average inner diameter of the channels is from 0.06 to 500.

8 . The structured catalyst for oxidation for exhaust gas purification according to claim 3 , wherein the average particle size of the metal nanoparticles is from 0.08 nm to 30 nm.

9 . The structured catalyst for oxidation for exhaust gas purification according to claim 3 , wherein the ratio of the average particle size of the metal nanoparticles to the average inner diameter of the channels is from 0.05 to 300.

10 . The structured catalyst for oxidation for exhaust gas purification according to claim 1 , further comprising at least another one functional substance held on an outer surface of the support.

11 . The structured catalyst for oxidation for exhaust gas purification according to claim 10 , wherein the content of the at least one oxidation catalyst present in the support is greater than that of at least the other one functional substance held on the outer surface of the support.

12 . An automobile exhaust gas treatment device comprising the structured catalyst for oxidation for exhaust gas purification described in claim 1 .

13 . A catalytic molding comprising a honeycomb substrate and the structured catalyst for oxidation for exhaust gas purification described in claim 1 on a surface of the honeycomb substrate.

14 . A method for producing a structured catalyst for oxidation for exhaust gas purification, comprising:
a calcination step of a precursor material (B) obtained by impregnating a precursor material (A) for obtaining a support of a porous structure composed of zeolite-type compound with a metal-containing solution; and a hydrothermal treatment step of hydrothermally treating a precursor material (C) obtained by calcining the precursor material (B) to obtain the support and an oxidation catalyst present in the support.

15 . The method for producing a structured catalyst for oxidation for exhaust gas purification according to claim 14 , further comprising a step of performing reduction treatment on the hydrothermally treated precursor material (C) after the hydrothermal treatment step.

16 . The method for producing a structured catalyst for oxidation for exhaust gas purification according to claim 14 , wherein 50 to 500 mass % of a non-ionic surfactant is added to the precursor material (A) before the calcination step.

17 . The method for producing a structured catalyst for oxidation for exhaust gas purification according to claim 14 , wherein the precursor material (A) is impregnated with the metal-containing solution by adding the metal-containing solution to the precursor material (A) in multiple portions before the calcination step.

18 . The method for producing a structured catalyst for oxidation for exhaust gas purification according to claim 14 , wherein in impregnating the precursor material (A) with the metal-containing solution before the calcination step, a value obtained by converting the added amount of the metal-containing solution added to the precursor material (A) to a ratio of silicon (Si) constituting the precursor material (A) to a metal element (M) included in the metal-containing solution added to the precursor material (A) (a ratio of number of atoms Si/M) is adjusted to from 10 to 1000.

19 . A gas purification method for purifying a gas containing carbon monoxide and hydrocarbon using a structured catalyst, wherein
the structured catalyst includes a support of a porous structure composed of a zeolite-type compound, and at least one type of oxidation catalyst being present in the support and selected from the group consisting of metals and metal oxides, the support has channels that communicate with each other, and the oxidation catalyst is present in at least the channels of the support.

20 . The gas purification method according to claim 19 , wherein the structured catalyst is a structured catalyst for oxidation for exhaust gas purification described in claim 1 .

Assignees

• Furukawa Electric Co Ltd

Inventors

• Masuda Takao
• Nakasaka Yuta
• Yoshikawa Takuya
• Kato Sadahiro
• Fukushima Masayuki
• Takahashi Hiroko
• BANBA Yuichiro
• Sekine Kaori

Classifications

• F01N2510/063

  zeolites · CPC title

• F01N2330/06

  Ceramic, e.g. monoliths · CPC title

• B01J37/0205

  in several steps · CPC title

• B01D53/944

  Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts (three-way-catalysts [TWC] B01D53/9445) · CPC title

• B01J29/68

  Iron group metals or copper · CPC title