Nitride stabilized core/shell nanoparticles

Patent metadata

Field	Value
Publication number	US-9882222-B2
Application number	US-201414554583-A
Country	US
Kind code	B2
Filing date	Nov 26, 2014
Priority date	Nov 27, 2013
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

Nitride stabilized metal nanoparticles and methods for their manufacture are disclosed. In one embodiment the metal nanoparticles have a continuous and nonporous noble metal shell with a nitride-stabilized non-noble metal core. The nitride-stabilized core provides a stabilizing effect under high oxidizing conditions suppressing the noble metal dissolution during potential cycling. The nitride stabilized nanoparticles may be fabricated by a process in which a core is coated with a shell layer that encapsulates the entire core. Introduction of nitrogen into the core by annealing produces metal nitride(s) that are less susceptible to dissolution during potential cycling under high oxidizing conditions.

First claim

The invention claimed is:

1. A catalyst nanoparticle comprising:
a non-noble metal solid solution core with a size of less than 100 nm along at least one of three orthogonal axes, and
a continuous and nonporous noble metal shell surrounding the non-noble metal solid solution core;
wherein the non-noble metal solid solution core comprises a nitride of a non-noble metal selected from the group consisting of nickel (Ni) nitride, cobalt (Co) nitride, iron (Fe) nitride, copper (Cu) nitride and mixtures thereof.

2. The catalyst nanoparticle of claim 1 , wherein the catalyst nanoparticle is substantially spherical having an external diameter of less than 20 nm.

3. The catalyst nanoparticle of claim 1 , wherein, the nonporous noble metal shell has a thickness, of between 0.5 nm and 3 nm.

4. The catalyst nanoparticle of claim 1 , wherein the nonporous noble metal shell comprises at least one noble metal selected from the group consisting platinum (Pt), palladium (Pd), gold (Au), rhodium (Rh), iridium (Ir), ruthenium (Ru), silver (Ag), rhenium (Re), alloys and combinations thereof.

5. The catalyst nanoparticle of claim 4 , wherein the at least one noble metal comprises platinum (Pt).

6. The catalyst nanoparticle of claim 1 , wherein the nonporous noble metal shell comprises 1 to 12 monolayers of platinum (Pt).

7. The catalyst nanoparticle of claim 6 , wherein the nonporous noble metal shell comprises 2 to 4 monolayers of platinum (Pt).

8. The catalyst nanoparticle of claim 1 , wherein the non-noble metal solid solution core comprises nickel nitride Ni 4 N.

9. The catalyst nanoparticle of claim 8 , wherein an amount of nickel nitride Ni 4 N within the non-noble metal solid core is between 20 and 50% wt. %.

10. An energy conversion device comprising:
a first electrode;
a conducting electrolyte; and
a second electrode, wherein at least one of the first or second electrodes comprises a plurality of catalyst nanoparticles of claim 1 .

11. The energy conversion device of claim 10 , wherein the catalyst nanoparticle comprises platinum (Pt) shell having a shell wall thickness of 2 to 4 atomic layers and nickel (Ni) core comprises 5-50 wt. % nickel (Ni) nitride.

12. The energy conversion device of claim 11 , wherein the energy conversion device is a fuel cell.

Assignees

• Brookhaven Science Ass Llc

Inventors

• Kuttiyiel Kurian Abraham
• Sasaki Kotaro
• Adzic Radoslav R

Classifications

• H01M4/923

  Compounds thereof with non-metallic elements · CPC title

• H01M4/8657

  layered · CPC title

• B01J23/40

  of the platinum group metals · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M4/92 Primary

  Metals of platinum group (H01M4/94 {, H01M4/9058} take precedence) · CPC title