Ultra-low platinum group metal containing anode electrocatalysts for acid mediated proton exchange membrane fuel cells

Patent metadata

Field	Value
Publication number	US-2024222652-A1
Application number	US-202218550084-A
Country	US
Kind code	A1
Filing date	Mar 4, 2022
Priority date	Mar 10, 2021
Publication date	Jul 4, 2024
Grant date	—

Abstract

The invention relates to systems and methods for successful operation of acid mediated proton exchange membrane fuel cell (PEMFC), and highly efficient, earth-abundant, and ultra-low noble metal-containing, e.g., platinum group metal (PGM)-containing, electrocatalyst materials for anodic hydrogen oxidation reaction (HOR). The electrocatalyst materials include metal silicide alloy-based solid solutions of the general formula: (A (n-x) B x )Si y , wherein A is a transition metal element or mixture or alloy thereof, B is a noble metal element or mixture or alloy thereof, and each of n and x, is a positive integer or a positive fractional number, and y is a positive integer.

First claim

We claim:

1 . An anode electrocatalyst composition, comprising:
a metal silicide alloy-based solid solution of a general formula:
(A (n-x) B x )Si y
wherein A is a transition metal element or mixture or alloy thereof, B is a noble metal element or mixture or alloy thereof, and each of n and x is a positive integer or a positive fractional number, and y is a positive integer, and wherein the anode electrocatalyst is used in an acid mediated proton exchange membrane-based hydrogen oxidation reaction.

2 . The composition of claim 1 , wherein A is selected from the group consisting of Ti, Ta, Nb, V, W, Sr, Pb, Sb, Cr, Co, Sn, Fe, Mn, Mo, Ni, and mixtures and alloys thereof.

3 . The composition of claim 1 , wherein B is selected from the group consisting of Pt, Ir, Ru, Rh, Os, Pd, and mixtures and alloys thereof.

4 . The composition of claim 1 , wherein the metal silicide alloy-based solid solution has the general formula: (Ti (5-x) Pt x )Si 3 and x is from greater than 0 to less than 5.

5 . The composition of claim 4 , wherein x is a positive number from 0.2 to 0.5.

6 . The composition of claim 1 , wherein A, B and Si are in a dry form.

7 . The composition of claim 6 , wherein the dry form is selected from the group consisting of powder, particles, flakes, rods, tubes, granules, films, and mixtures and combinations thereof.

8 . The composition of claim 7 , wherein the dry form comprises one or more high specific surface area nanostructured forms.

9 . The composition of claim 1 , wherein the general formula corresponds to the elemental stoichiometry of A, B and Si.

10 . A method of preparing an anode electrocatalyst composition, comprising:
preparing a metal silicide alloy-based solid solution of the general formula:

(

A

(

n
-
x

)

⁢

B
x

)

⁢

Si
y

wherein A is a transition metal element or mixture or alloy thereof, B is a noble metal element or mixture or alloy thereof, each of n and x is a positive integer or a positive fractional number, and y is a positive integer, comprising:
obtaining A, B and Si in dry form;
combining the A, B and Si to form a dry mixture; and
high energy mechanical milling the dry mixture to form an alloy composition.

11 . The method of claim 10 , wherein the high energy mechanical milling, comprises loading the dry mixture into a vial containing stainless-steel balls.

12 . The method of claim 11 , wherein the weight ratio of stainless-steel balls to powder is 5:1.

13 . The method of claim 10 , wherein the dry form comprises one or more high specific surface area nanostructured forms.

14 . A proton exchange membrane fuel cell, comprising:
an anode electrocatalyst composition, comprising:
a metal silicide alloy-based solid solution of the general formula:

(

A

(

n
-
x

)

⁢

B
x

)

⁢

Si
y

wherein A is a transition metal element or mixture or alloy thereof, B is a noble metal element or mixture or alloy thereof, and each of n and x is a positive integer or a positive fractional number, and y is a positive integer.

15 . The fuel cell of claim 14 , wherein A is selected from the group consisting of Ti, Ta, Nb, V, W, Sr, Pb, Sb, Cr, Co, Sn, Fe, Mn, Mo, Ni, and mixtures and alloys thereof.

16 . The fuel cell of claim 14 , wherein B is selected from the group consisting of Pt, Ir, Ru, Rh, Os, Pd, and mixtures and alloys thereof.

17 . The fuel cell of claim 14 , wherein the metal silicide alloy-based solid solution has the general formula: (Ti (5-x) Pt x )Si 3 and x is from greater than 0 to less than 5.

18 . The fuel cell of claim 17 , wherein x is a positive number from 0.2 to 0.5.

19 . The fuel cell of claim 14 , wherein A, B and Si are in a dry form.

20 . The fuel cell of claim 19 , wherein the dry form is selected from the group consisting of powder, particles, flakes, rods, tubes, granules, films, and mixtures and combinations thereof.

21 . The fuel cell of claim 14 , wherein the dry form comprises one or more high specific surface area nanostructured forms.

22 . The fuel cell of claim 14 , wherein the general formula corresponds to the elemental stoichiometry of A, B and Si.

Assignees

• Univ Pittsburgh Commonwealth Sys Higher Education

Inventors

• Kumta Prashant N
• Ghadge Shrinath Dattatray
• Velikokhatnyi Oleg
• Datta Moni Kanchan

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M4/923

  Compounds thereof with non-metallic elements · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2004/03

  obtained by SEM · CPC title

• C01P2002/85

  by XPS, EDX or EDAX data · CPC title