Electrocatalyst including metal core coated with noble metal shell, method of preparation, and fuel cell using the same

Patent metadata

Field	Value
Publication number	US-12068488-B2
Application number	US-202117519193-A
Country	US
Kind code	B2
Filing date	Nov 4, 2021
Priority date	Aug 26, 2016
Publication date	Aug 20, 2024
Grant date	Aug 20, 2024

Abstract

A composition comprised of a tin (Sn) or lead (Pb) film, wherein the film is coated by a shell, wherein the shell: (a) is comprised of an active metal, and (b) is characterized by a thickness of less than 50 nm, is discloses herein. Further disclosed herein is the use of the composition for the oxidation of e.g., methanol, ethanol, formic acid, formaldehyde, dimethyl ether, methyl formate, and glucose.

First claim

What is claimed is:

1. A composition comprising:
metal nanoparticles (NP) coated by a shell, wherein:
a metal of said metal NPs is in an elemental state and is selected from the group consisting of: tin (Sn), lead (Pb), antimony (Sb) and a combination thereof;
said shell: (a) is a noble metal-Sn alloy, and (b) is characterized by an average thickness of less than 50 nm.

2. The composition of claim 1 , wherein said metal is Sn.

3. The composition of claim 1 , wherein a molar ratio between Sn and the noble metal within the noble metal-Sn alloy is between 5:1 and 1:1.

4. The composition of claim 1 , wherein a median size of said metal nanoparticles is from 1 to 50 nanometers.

5. A composition comprising:
metal nanoparticles (NP) coated by a shell, wherein:
each of said NP consists of a metal in an elemental state selected from the group consisting of: tin (Sn), lead (Pb) and a combination thereof;
said shell: (a) comprises a noble metal, and (b) is characterized by an average thickness of between 13 and 50 nm; and
wherein a molar ratio between said metal and said noble metal within each of said NP is between 2:1 and 10:1, respectively.

6. The composition of claim 5 , wherein said metal is Sn.

7. The composition of claim 5 , wherein a median size of said metal nanoparticles is from 15 to 50 nanometers.

8. The composition of claim 5 , wherein said shell further comprises a material selected from the group consisting of Sn, Pb, Sb, Mo, Co, Fe, Mn, Os, Ni, Ti, W, indium-tin-oxide and selenium (Se), including any oxide or a combination thereof.

9. The composition of claim 5 , wherein said noble metal is selected from the group consisting of: platinum (Pt), palladium (Pd), ruthenium (Ru), gold (Au), silver (Ag), rhodium (Rh), iridium (Ir), or an alloy or a combination thereof.

10. The composition of claim 9 , wherein said noble metal consists of Pt and Pd in a molar ratio of from 3:1 to 1:3, respectively.

11. The composition of claim 5 , wherein said composition is in a form of an electrocatalyst configured for oxidation of a fuel.

12. The composition of claim 11 , wherein said fuel is selected from the group consisting of methanol, ethanol, formic acid, formaldehyde, dimethyl ether, methyl formate, and glucose.

13. A process for manufacturing metal nanoparticles (NP) coated by a shell comprising a noble metal, and characterized by an average thickness of between 1 and 50 nm; the process comprises:
(i) providing metal NPs comprising an elemental state metal selected from the group consisting of: tin (Sn), lead (Pb), antimony (Sb) and a combination thereof; and
(ii) plating a material comprising said noble metal on said metal NPs by electroless plating, thereby obtaining said metal NPs coated by the shell; wherein said electroless plating is performed in an acidic noble metal salt solution.

14. The process of claim 13 , wherein the elemental state metal is Sn, and wherein said acidic noble metal salt solution further comprises a glycol.

15. The process of claim 13 ,
wherein said acid noble metal salt solution comprises sulfuric acid or perchloric acid.

16. The process of claim 13 , wherein said metal NPs of step (i) further comprise an oxide layer, and wherein step (ii) is performed for a time period sufficient for removing said oxide layer, thereby inducing deposition of said noble metal on a surface of said elemental state metal.

Assignees

• Ariel Scient Innovations Ltd

Inventors

• Schechter Alex
• Teller Hanan
• Kashyap Diwakar

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M2004/8684

  Negative electrodes · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• C22C5/04

  Alloys based on a platinum group metal · CPC title

• C23C18/42

  Coating with noble metals · CPC title