Method for preparation gaseous-nitridation treated or liquid-nitridation treated core-shell catalyst

Patent metadata

Field	Value
Publication number	US-11813600-B2
Application number	US-201816767721-A
Country	US
Kind code	B2
Filing date	Jul 5, 2018
Priority date	Nov 29, 2017
Publication date	Nov 14, 2023
Grant date	Nov 14, 2023

Abstract

The present disclosure is related to a method for preparing a gaseous- or liquid-nitridation treated core-shell catalyst and, more specifically, to a method for preparing a gaseous- or liquid-nitridation treated core-shell catalyst comprising steps of: nitridation-treating a transition metal precursor core and noble metal precursor shell particles in the presence of a gaseous nitrogen source; or forming a transition metal precursor core and noble metal precursor shell particles, by means of a liquid nitrogen source, and at the same time allowing the nitrogen source to bond with the transition metal precursor and thus allowing nitridation treatment. Therefore, the present disclosure allows a high nitrogen content in the core and thus enables a prepared catalyst to have excellent durability, a small average particle size and high degree of dispersion and uniformity, and thus to be suitable for the fuel cell field.

First claim

The invention claimed is:

1. A method for preparing a liquid-nitridation treated core-shell catalyst, the method comprising the steps of:
irradiating ultrasonic waves to a solution including liquid-urea as a nitrogen source, a reducing solvent, a noble metal precursor, a transition metal precursor and a carbon support at 150 to 200° C.; and
forming a cavity and forming transition metal precursor core and noble metal precursor shell particles due to a difference in vapor pressures while nitridation treating the transition metal precursor by combining with liquid-urea, to prepare a core-shell catalys, wherein
a nitrogen atom is maintained in a molar ratio 10.5 to 41.1 moles per 58.9 to 89.5 moles of the transition metal,
an average particle diameter of the prepared core-shell catalyst is 4.0 nm or less,
the transition metal precursor is at least one kind selected from the group consisting of an acethylacetonate precursor of the transition metal and a hexafluoroacetylacetonate precursor of the transition metal,
the noble metal precursor is at least one kind selected from the group consisting of an acetylacetonate precursor of the noble metal, a hexafluoroacetylacetonate precursor of the noble metal and pentafluoroacetylacetonate precursor of the noble metal, and
the reducing solvent has a reducing power at a high temperature of 70° C. or higher, and is at least one kind of ethylene glycols selected from the group consisting of di-ethylene glycol, tri-ethylene glycol and poly-ethylene glycol.

2. The method for preparing a liquid-nitridation treated core-shell catalyst according to claim 1 , wherein the carbon support is a porous support.

3. The method for preparing a liquid-nitridation treated core-shell catalyst according to claim 1 , wherein the core-shell catalyst is made up of a cobalt core and a platimum shell.

4. The method for preparing a liquid-nitridation treated core-shell catalyst according to claim 1 , wherein the core-shell catalyst is made up of a nickel core and a platinum shell.

Assignees

• Korea Inst Energy Res

Inventors

• Park Gu-Gon
• Lee Eun-Jik
• Park Dong-Chul
• Yim Sung-Dae
• Kim Chang-Soo
• Lee Won-Yong
• Yang Tae-Hyun
• Park Seok-Hee
• Kim Min-Jin
• Sohn Young-Jun
• Bae Byung-Chan
• Kim Seung-Gon
• Shin Dong-Won
• Oh Hwan-Yeong

Classifications

• B01J2235/15

  X-ray diffraction · CPC title

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• B01J35/45

  Nanoparticles · CPC title

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J21/18

  Carbon · CPC title