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

Patent metadata

Field	Value
Publication number	US-2020346199-A1
Application number	US-201816767721-A
Country	US
Kind code	A1
Filing date	Jul 5, 2018
Priority date	Nov 29, 2017
Publication date	Nov 5, 2020
Grant date	—

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

1 . A method for preparing a gaseous-nitridation treated core-shell catalyst comprising steps of:
irradiating ultrasonic waves to a solution including a reducing solvent, a noble metal precursor, a transition metal precursor and a carbon support, thus forming a cavity and forming transition metal precursor core and noble metal precursor shell particles due to a difference in vapor pressures; and nitridation treating the transition metal precursor core and noble metal precursor shell particles at a temperature of 250 to 550° C. in a pressure condition of 1 to 120 bars under a gaseous nitrogen source thus maintaining a nitrogen atom being in a molar ratio of 10 to 50 per 50 to 90 moles of the transition metal.

2 . The method for preparing a gaseous-nitridation treated core-shell catalyst according to claim 1 , characterized in that the gaseous nitrogen source is selected from the group consisting of ammonia, urethane and melamine.

3 . The method for preparing a gaseous-nitridation treated core-shell catalyst according to claim 1 , characterized in that an average particle diameter of the gaseous-nitridation treated core-shell catalyst is 5.0 nm or less.

4 . The method for preparing a gaseous-nitridation treated core-shell catalyst according to claim 1 , characterized in that a specific activity of the gaseous-nitridation treated core-shell catalyst is maintained being 1.5 to 4 times higher compared a platinum single metal.

5 . The method for preparing a gaseous-nitridation treated core-shell catalyst according to claim 1 , characterized in that the reducing solvent has a reducing power at a high temperature of 70° C. or higher.

6 . The method for preparing a gaseous-nitridation treated core-shell catalyst according to 30 claim 1 , characterized in that the carbon support is a porous support.

7 . The method for preparing a gaseous-nitridation treated core-shell catalyst according to claim 1 , characterized in that the core-shell catalyst is made up of a cobalt core and a platinum shell.

8 . The method for preparing a gaseous-nitridation treated core-shell catalyst according to claim 1 , characterized in that the core-shell catalyst is made up of a nickel core and a platinum shell.

9 . A method for preparing a liquid-nitridation treated cores-shell catalyst comprising steps:
irradiating ultrasonic waves to a solution including a liquid nitrogen source, a reducing solvent, a noble metal precursor, a transition metal precursor and a carbon support; and forming a cavity by the ultrasonic irradiation and forming transition metal precursor core and noble metal precursor shell particles due to a difference in vapor pressure while nitridation treating the transition metal precursor by combining with the nitrogen source.

10 . The method for preparing a liquid-nitridation treated core-shell catalyst according to claim 9 , characterized in that a nitrogen atom is maintained in a molar ratio of 10 to 50 per 50 to 90 moles of the transition metal.

11 . The method for preparing a liquid-nitridation treated core-shell catalyst according to claim 9 , characterized in that the liquid nitrogen source is a urea or ammonia solution or a mixture thereof.

12 . The method for preparing a liquid-nitridation treated core-shell catalyst according to claim 9 , characterized in that an average particle diameter of the liquid-nitridation treated core-shell catalyst is 4.0 nm or less.

13 . The method for preparing a liquid-nitridation treated core-shell catalyst according to claim 9 , characterized in that the reducing solvent has a reducing power at a high temperature of 70° C. or higher.

14 . The method for preparing a liquid-nitridation treated core-shell catalyst according to claim 9 , characterized in that the carbon support is a porous support.

15 . The method for preparing a gaseous-nitridation treated core-shell catalyst according to claim 9 , characterized in that the core-shell catalyst is made up of a cobalt core and a platinum shell.

16 . The method for preparing a gaseous-nitridation treated core-shell catalyst according to claim 9 , characterized in that 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