INTERMETALLIC L10-NiPtAg CATALYSTS FOR OXYGEN REDUCTION REACTION

Patent metadata

Field	Value
Publication number	US-2021184227-A1
Application number	US-201916716127-A
Country	US
Kind code	A1
Filing date	Dec 16, 2019
Priority date	Dec 16, 2019
Publication date	Jun 17, 2021
Grant date	—

Abstract

An electrode catalyst for an oxygen reduction reaction including intermetallic L10-NiPtAg alloy nanoparticles having enhanced ORR activity and durability. The catalyst including intermetallic L10-NiPtAg alloy nanoparticles is synthesized by employing silver (Ag) as a dopant and annealing under specific conditions to form the intermetallic structure. In one example, the intermetallic L10-NiPtAg alloy nanoparticles are represented by the formula: NixPtyAgz wherein 0.4≤x≤0.6, 0.4≤y≤0.6, z≤0.1.

First claim

What is claimed is:

1 . An electrode catalyst for oxygen reduction reaction comprising intermetallic L1 0 -NiPtAg alloy nanoparticles, having mass activity (MA) of greater than 1000 A/g Pt .

2 . The catalyst according to claim 1 , wherein the intermetallic L1 0 -NiPtAg alloy nanoparticles have mass activity (MA) greater than 1100 A/g Pt .

3 . The catalyst according to claim 1 , wherein the intermetallic L1 0 -NiPtAg alloy nanoparticles have mass activity (MA) retention greater than 40%.

4 . The catalyst according to claim 1 , wherein the intermetallic L1 0 -NiPtAg alloy nanoparticles have mass activity (MA) retention greater than 45%.

5 . The catalyst according to claim 1 , wherein the intermetallic L1 0 -NiPtAg alloy nanoparticles are represented by the formula: Ni x Pt y Ag z , wherein 0.4≤x≤0.6, 0.4≤y≤0.6, z≤0.1.

6 . A method for the synthesis of a catalyst comprising intermetallic L1 0 -NiPtAg alloy nanoparticles represented by the formula: Ni x Pt y Ag z wherein 0.4≤x≤0.6, 0.4≤y≤0.6, z≤0.1, said method comprising:
forming a NiPt alloy system by co-reduction of reducible metal precursors;
doping the NiPt alloy system with silver (Ag) to form NiPtAg alloy nanoparticles;
loading the NiPtAg alloy nanoparticles onto a carbon support and annealing at a temperature in the range of 300° C. to about 630° C. for at least 6 hours to form the L1 0 -NiPtAg intermetallic structure.

7 . The method according to claim 6 , wherein the annealing is at a temperature in the range of from about 500° C. to about 600° C.

8 . The method according to claim 6 , wherein the annealing is at a temperature in the range of from about 550° C. to about 600° C.

9 . The method according to claim 6 , wherein the annealing is at a temperature of about 550° C.

10 . The method according to claim 6 , wherein the intermetallic L1 0 -NiPtAg alloy nanoparticles have mass activity (MA) greater than 1100 A/g Pt .

11 . The method according to claim 6 , wherein the intermetallic L1 0 -NiPtAg alloy nanoparticles have mass activity (MA) retention greater than 40%.

12 . The method according to claim 6 , wherein the intermetallic L1 0 -NiPtAg alloy nanoparticles have mass activity (MA) retention greater than 45%.

Assignees

• Toyota Eng & Mfg North America

Inventors

• Wei Kecheng
• Nagai Tomoyuki
• Zhou Li Qin
• Jia Hongfei

Classifications

• B22F1/17

  Metallic particles coated with metal · CPC title

• B22F1/054

  Nanosized particles · CPC title

• H01M4/921 Primary

  Alloys or mixtures with metallic elements · CPC title

• B22F9/24

  starting from liquid metal compounds, e.g. solutions · CPC title

• C22C5/04

  Alloys based on a platinum group metal · CPC title