Electro-catalytic conformal coatings and method for making the same

1. An electrode of comprising:

a porous mixed ionic-electronic conductor (MIEC); and

an oxygen-reducing catalyst coating having a thickness in a range from about 1 to about 50 nm;

wherein the oxygen-reducing catalyst coating comprises a perovskite having a composition A 1−x A′ x BO 3−δ ;

wherein A comprises a praseodymium (Pr) element at the A-site of the perovskite, A′ comprises a strontium (Sr) element at the A-site of the perovskite, and B comprises a manganese (Mn) element at the B-site of the perovskite; and

wherein 0≤x<1.

2. An electrode comprising:

a porous mixed ionic-electronic conductor (MIEC); and

an oxygen-reducing catalyst coating having a thickness in a range from about 1 to about 50 nm;

wherein the oxygen-reducing catalyst coating comprises a perovskite having a composition A 2−x A′ x B 2−y B′ y O 6−δ ;

wherein A comprises a praseodymium (Pr) element at the A-site of the perovskite, A′ comprises a strontium (Sr) element at the A-site of the perovskite, B comprises a cobalt (Co) element at the B-site of the perovskite, and B′ comprises a manganese (Mn) element at the B-site of the perovskite; and

wherein 0<x≤1.2 and 0<y<2.

3. The electrode of claim 2 , wherein x>0 and y>0, such that the oxygen-reducing catalyst coating is praseodymium strontium cobalt manganese (PSCM).

4. The electrode of claim 2 , wherein 0.2<x≤1.2 and 0.2<y<1.9.

5. The electrode of claim 2 , wherein 0.4<x≤1.1 and 0.8<y<1.2.

6. The electrode of claim 2 , wherein x=1 and y=1.

7. A solid-oxide fuel cell comprising:

an electrolyte;

an anode electrically coupled to a first surface of the electrolyte; and

a cathode electrically coupled to a second surface of the electrolyte, the cathode comprising the electrode of claim 1 .

8. The electrode of claim 1 , wherein the porous mixed ionic-electronic conductor is selected from a group consisting of lanthanum strontium manganite (LSM), lanthanum strontium cobalt ferrite (LSCF), strontium-doped samarium cobaltite (SSC), barium strontium cobalt ferrite (BSCF), praseodymium barium cobalt (PBC) and their derivatives.

9. The electrode of claim 1 , wherein the oxygen-reducing catalyst coating is a continuous film.

10. The electrode of claim 1 , wherein the electrode has a first interfacial resistance less than or equal to about 0.1 Ωcm 2 at about 750° C.

11. The electrode of claim 1 , wherein x>0, such that the oxygen-reducing catalyst coating is praseodymium strontium manganese (PSM).

12. The electrode of 1 , wherein x<0.5.

13. The electrode of claim 1 , wherein 0.1<x<0.3.

14. The electrode of claim 1 , wherein x=0.25.

15. The electrode of claim 2 , wherein the porous mixed ionic-electronic conductor is selected from a group consisting of lanthanum strontium manganite (LSM), lanthanum strontium cobalt ferrite (LSCF), strontium-doped samarium cobaltite (SSC), barium strontium cobalt ferrite (BSCF), praseodymium barium cobalt (PBC) and their derivatives.

16. The electrode of claim 2 , wherein the oxygen-reducing catalyst coating is a continuous film.

17. The electrode of claim 2 , wherein the electrode has a first interfacial resistance less than or equal to about 0.1 Ωcm 2 at about 750° C.

18. A solid-oxide fuel cell comprising:

an electrolyte;

an anode electrically coupled to a first surface of the electrolyte; and

a cathode electrically coupled to a second surface of the electrolyte, the cathode comprising the electrode of claim 2 .