Materials for ammonia synthesis

Patent metadata

Field	Value
Publication number	US-11674231-B2
Application number	US-202016742390-A
Country	US
Kind code	B2
Filing date	Jan 14, 2020
Priority date	Jan 14, 2019
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

Disclosed herein are doped perovskite oxides. The doped perovskite oxides may be used as a cathode material in an electrochemical cell to electrochemically generate ammonia from N2. The doped perovskite oxides may be combined with nitride compounds, for instance iron nitride, to further increase the efficiency of the ammonia production.

First claim

What is claimed is:

1. A cathode comprising a perovskite oxide having the formula:
A 1 w A 2 x X y Fe z O 3
wherein:
A 1 is selected from La, Tb, Gd, Sm, Pr, and Nd;
A 2 is selected from Sr, Mg, Ca, and Ba;
X is one or more metals in the +1 or +2 oxidation state;
w is from 0.5-1.0;
x is from 0-0.5;
y is from 0-0.5; and
z is from 0.5 to less than 1.0;
wherein w, x, y, and z are chosen to maintain electroneutrality; and
one or more nitride compounds having the formula M a N b , wherein M is selected from Fe, Mb, Co, Cr, and V, a is selected from 1, 2, 3, or and 4, and b is selected from 1, 2, 3, and 4.

2. The cathode of claim 1 , wherein M is Fe.

3. The cathode of claim 1 , wherein the weight ratio of perovskite oxide to nitride compound is from 10:1 to 1:10.

4. A solid oxide electrolyte cell comprising:
(a) the cathode of claim 1 ;
(b) an anode; and
(c) an electrolyte disposed between the cathode and anode;
wherein the cathode and anode are in electrical communication with a power supply configured to provide a voltage potential between the cathode and anode.

5. The cell of claim 4 , wherein the electrolyte is an oxygen-ion conducting solid electrolyte.

6. The cell of claim 4 , wherein the electrolyte comprises yttria stabilized zirconia (YSZ), scandia stabilized zirconia (ScSZ), gadolinium doped ceria (GDC), perovskite-type oxides such as lanthanum strontium gallium magnesium oxide (LSGM), lanthanum yttrium germanate (LaYGe), or a combination thereof.

7. The cell of claim 4 , wherein the anode comprises a combination of a lanthanum strontium manganate-type perovskite and at least one doped fluorite oxide, for instance yttria stabilized zirconia, GDC, and ABO 3 -type perovskite oxides where A is selected from alkaline earth metals and lanthanoids and B is one or more transition metals.

8. The cell of claim 4 , wherein the anode comprises palladium, platinum, silver, gold, yttria stabilized zirconia, lanthanum strontium manganate, or a combination thereof.

Assignees

• Ohio State Innovation Foundation
• Obio State Innovation Found

Inventors

• Ozkan Umit
• Gunduz Seval
• Deka Dhruba Jyoti

Classifications

• C01P2002/34

  perovskite-type (ABO3) · CPC title

• C04B2235/3203

  Lithium oxide or oxide-forming salts thereof · CPC title

• C25B11/047

  Ceramics · CPC title

• C04B2235/3256

  Molybdenum oxides, molybdates or oxide forming salts thereof, e.g. cadmium molybdate · CPC title

• C04B2235/3287

  Germanium oxides, germanates or oxide forming salts thereof, e.g. copper germanate · CPC title