Antioxidant for fuel cell having antioxidative property and proton conductivity and producing method thereof

1 . An antioxidant for a fuel cell, comprising:

a metal oxide; and

a proton conductive functional group bonded to the metal oxide,

wherein the proton conductive functional group comprises a sulfonic acid group attached to the metal oxide by a sulfonation bond,

wherein the proton conductive functional group is represented by the following Formula 1:

wherein * is a connection site to the metal oxide, and

n is an integer of 1 to 10.

2 . The antioxidant of claim 1 , wherein the metal oxide comprises one or more selected from the group consisting of cerium oxide, cerium zirconium oxide, gadolinium doped cerium oxide, samarium doped cerium oxide, cerium oxide supported by titanium oxide, and cerium oxide supported by silicon oxide.

3 . The antioxidant of claim 1 , wherein the metal oxide has a crystal size of about 10 nm to 100 nm as measured by X-ray diffraction.

4 . The antioxidant of claim 1 , wherein the proton conductive functional group comprises:

the sulfonic acid group; and

a linker connecting the metal oxide and the sulfonic acid group in the proton conductive functional group.

5 . The antioxidant of claim 1 , wherein the antioxidant satisfies the following conditions 1 and 2:

I 0,1 >I 1,1   (Condition 1)

I 0,2 <I 1,2   (Condition 2)

in condition 1, I 0,1 is a height of a peak found in a wavenumber region of 3,400 cm −1 ±100 cm −1 in an infrared spectral spectrum for the metal oxide, and I 1,1 is a height of a peak found in a wavenumber region of 3,400 cm −1 ±100 cm −1 in an infrared spectral spectrum for the antioxidant, and

in condition 2, I 0,2 is a height of a peak found in a wavenumber region of 1,170 cm −1 ±100 cm −1 in an infrared spectral spectrum for the metal oxide, and I 1,2 is a height of a peak found in a wavenumber region of 1,170 cm −1 ±100 cm −1 in an infrared spectral spectrum for the antioxidant.

6 . A fuel cell, comprising:

an electrolyte membrane comprising an ionomer;

a cathode disposed on one surface of the electrolyte membrane; and

an anode disposed on the other surface of the electrolyte membrane,

wherein at least one of the electrolyte membrane, the cathode, and the anode comprises the antioxidant according to claim 1 .

7 . The fuel cell of claim 6 , wherein the electrolyte membrane comprises an amount of about 0.1 parts by weight to 10 parts by weight of the antioxidant based on 100 parts by weight of the ionomer.

8 . A method of producing an antioxidant for a fuel cell, comprising:

preparing an admixture including metal oxide, sultone, and a solvent; and

reacting the admixture,

wherein a proton conductive functional group comprising a sulfonic acid group is attached to the metal oxide by a sulfonation bond.

9 . The method of claim 8 , wherein the solvent comprises toluene.

10 . The method of claim 8 , wherein the solvent does not comprises an aqueous solvent.

11 . The method of claim 8 , wherein the metal oxide comprises one or more selected from the group consisting of cerium oxide, cerium zirconium oxide, gadolinium doped cerium oxide, samarium doped cerium oxide, cerium oxide supported by titanium oxide, and cerium oxide supported by silicon oxide.

12 . The method of claim 8 , wherein the metal oxide has a crystal size of about 10 nm to 100 nm as measured by X-ray diffraction.

13 . The method of claim 8 , wherein the sultone comprises a compound represented by the following Formula 2:

wherein m is an integer of 1 to 10.

14 . The method of claim 8 , wherein the proton conductive functional group is represented by the following Formula 1:

wherein * is a connection site to the metal oxide, and

n is an integer of 1 to 10.

15 . The method of claim 8 , wherein the antioxidant satisfies the following conditions 1 and 2:

I 0,1 >I 1,1   (Condition 1)

I 0,2 <I 1,2   (Condition 2)

in condition 1, I 0,1 is a height of a peak found in a wavenumber region of 3,400 cm −1 ±100 cm −1 in an infrared spectral spectrum for the metal oxide, and I 1,1 is a height of a peak found in a wavenumber region of 3,400 cm −1 ±100 cm −1 in an infrared spectral spectrum for the antioxidant, and

in condition 2, I 0,2 is a height of a peak found in a wavenumber region of 1,170 cm −1 ±100 cm −1 in an infrared spectral spectrum for the metal oxide, and I 1,2 is a height of a peak found in a wavenumber region of 1,170 cm −1 ±100 cm −1 in an infrared spectral spectrum for the antioxidant.

16 . A vehicle comprising a fuel cell of claim 6 .