Pd-SUPPORTING Zr-BASED COMPOSITE OXIDE

Patent metadata

Field	Value
Publication number	US-2019336945-A1
Application number	US-201616061493-A
Country	US
Kind code	A1
Filing date	Dec 26, 2016
Priority date	Jan 28, 2016
Publication date	Nov 7, 2019
Grant date	—

Abstract

A Pd-supporting Zr-based composite oxide wherein by having a Zr-containing composite oxide support and Pd supported thereon and by showing, upon XAFS (X-ray absorption fine structure) analysis, a maximum peak in a Pd bond distance range of 2.500-3.500 Å, the maximum peak being located in a position of 3.050-3.110 Å.

First claim

1 - 4 . (canceled)

5 . A Pd-supporting Zr-based composite oxide,
wherein Pd is supported on a Zr-containing composite oxide support, and wherein the location of the maximum peak in a Pd bond distance range of 2.500 Å to 3.500 Å, is 3.050 Å to 3.110 Å, as determined by XAFS (X-Ray Absorption Fine Structure) analysis.

6 . The Pd-supporting Zr-based composite oxide according to claim 5 ,
wherein the location of the maximum peak in a Pd bond distance range of 2.500 Å to 3.500 Å, is 3.060 Å to 3.100 Å, as determined by XAFS analysis.

7 . The Pd-supporting Zr-based composite oxide according to claim 5 ,
wherein the Zr content in terms of ZrO2 is 1 mass % or more and 90 mass % or less, wherein the Ce content in terms of CeO2 is 90 mass % or less, and wherein the total of the Zr content in terms of ZrO2 and the Ce content in terms of CeO2 is 80 mass % or more, the total mass of the composite oxide support being defined as 100 mass %.

8 . The Pd-supporting Zr-based composite oxide according to claim 7 ,
wherein the Zr content in terms of ZrO2 is 2 mass % or more and 85 mass % or less, the total mass of the composite oxide support being defined as 100 mass %.

9 . The Pd-supporting Zr-based composite oxide according to claim 7 ,
wherein the Ce content in terms of CeO2 is 5 mass % or more and 80 mass % or less, the total mass of the composite oxide support being defined as 100 mass %.

10 . The Pd-supporting Zr-based composite oxide according to claim 5 ,
wherein the composite oxide support comprises a rare earth element (Ln) excluding Ce.

11 . The Pd-supporting Zr-based composite oxide according to claim 10 ,
wherein the rare earth element (Ln) excluding Ce is one or more rare earth elements selected from among Y, La, Pr, Nd and Eu.

12 . The Pd-supporting Zr-based composite oxide according to claim 10 ,
wherein the content of rare earth element (Ln) excluding Ce in terms of Ln2O3 is 1 mass % or more and 20 mass % or less, the total mass of the composite oxide support being defined as 100 mass %.

13 . The Pd-supporting Zr-based composite oxide according to claim 5 wherein the Pd supporting mass in terms of Pd metal is 0.75 mass % or more and 3.0 mass % or less, with respect to the composite oxide support.

14 . An exhaust gas purification catalyst, comprising the Pd-supporting Zr-based composite oxide according to claim 5 .

15 . The exhaust gas purification catalyst according claim 14 ,
wherein the catalyst has a monolayer or multilayer structure onto a base material, and at least one of the layers is a coated layer of the Pd-supporting Zr-based composite oxide.

16 . A method for producing the Pd-supporting Zr-based composite oxide according to claim 5 ,
wherein the method comprises the following steps in order: a first step of heat treating an aqueous solution comprising a zirconium oxide precursor to form a Zr-containing sol, a second step of adding a palladium precursor to the Zr-containing sol obtained in the first step to obtain a Pd-added Zr-containing sol, a third step of contacting the Pd-added Zr-containing sol obtained in the second step with a basic compound to obtain a precipitate, and a fourth step of firing the precipitate obtained in the third step.

17 . The method according to claim 16 ,
wherein the zirconium oxide precursor is selected from zirconium nitrate, zirconium oxynitrate, zirconium sulfate and zirconium acetate.

18 . The method according to claim 16 ,
wherein the Pd-added Zr-containing sol is contacted with a pore-forming agent which is a long-chain fatty acid, in combination with the basic compound to obtain a precipitate, in the third step.

Assignees

• Cataler Corp
• Santoku Corp

Inventors

• Murakami Kyosuke
• Narita Keiichi
• Matsueda Satoshi
• Tanaka Michio
• Murota Tadatoshi
• Ono Shigeru
• Tahara Tomonori

Classifications

• B01D2255/2061

  Yttrium · CPC title

• B01J37/0018

  Addition of a binding agent or of material, later completely removed among others as result of heat treatment, leaching or washing,(e.g. forming of pores; protective layer, desintegrating by heat) · CPC title

• F01N3/10

  by thermal or catalytic conversion of noxious components of exhaust · CPC title

• F01N3/28

  Construction of catalytic reactors · CPC title

• F01N2370/02

  used in catalytic reactors · CPC title