Metal-metal bonded ammonia oxidation catalysts

Patent metadata

Field	Value
Publication number	US-12515207-B2
Application number	US-202217939405-A
Country	US
Kind code	B2
Filing date	Sep 7, 2022
Priority date	Oct 23, 2019
Publication date	Jan 6, 2026
Grant date	Jan 6, 2026

Abstract

Methods and catalysts for oxidizing ammonia to nitrogen are described. Specifically, diruthenium complexes that spontaneously catalyze this reaction are disclosed. Accordingly, the disclosed methods and catalysts can be used in various electrochemical cell-based energy storage and energy production applications that could form the basis for a potential nitrogen economy.

First claim

We claim:

1 . An electrochemical half-cell comprising:
n anode electrode in contact with a catalyst comprising a diruthenium complex, wherein the catalyst is capable of spontaneously catalyzing the oxidation of NH 3 to N 2 ; wherein the diruthenium complex comprises a central metal-metal bonded diruthenium of [Ru] 2 n+ , where n is 3-7; and wherein the diruthenium complex has the chemical structure:

wherein:
L, which may or may not be present, is, if present, a non-competitive ligand;
each E, which may be the same or different, is independently O, S, NH or NY, where Y is an alkyl or an aryl;
each X, which may be the same or different, is a steric tuning group; and
R, which may or may not be present, is (if present) an electronic tuning group.

2 . The electrochemical half-cell of claim 1 , wherein the anode electrode is further in contact with NH 3 .

3 . The electrochemical half-cell of claim 1 , wherein L is BF 4 , CI, OCH 3 (OMe), tetrahydrofuran (THF), pyridine, trifluoromethanesulfonate (OTf) or NH 3 .

4 . The electrochemical half-cell of claim 3 , wherein L is OTf; each E is O; each X is CI, F, or Me; and R is not present.

5 . The electrochemical half-cell of claim 4 , wherein each X is Cl.

6 . The electrochemical half-cell of claim 4 , wherein each X is F.

7 . The electrochemical half-cell of claim 4 , wherein each X is Me.

8 . The electrochemical half-cell of claim 3 , wherein L is NH 3 ; each E is O; each X is CI, F, or Me; and R is not present.

9 . The electrochemical half-cell of claim 8 , wherein each X is Cl.

10 . The electrochemical half-cell of claim 8 , wherein each X is F.

11 . The electrochemical half-cell of claim 8 , wherein each X is Me.

12 . An electrochemical cell comprising the electrochemical half-cell of claim 1 that is in fluid, ionic and/or electrical communication with an electrochemical half-cell comprising a cathode electrode.

13 . The electrochemical cell of claim 12 , wherein the electrochemical cell is an energy storage cell, a fuel cell, or an electrosynthetic cell.

14 . The electrochemical cell of claim 12 , wherein the electrochemical cell includes a membrane or barrier separating the anode electrode and the cathode electrode.

15 . The electrochemical cell of claim 12 , wherein the cathode electrode comprises a catalyst capable of catalyzing the reduction of O 2 to H 2 O.

16 . The electrochemical cell of claim 15 , wherein in operation, O 2 is being reduced to H 2 O at the cathode electrode.

17 . The electrochemical cell of claim 12 , wherein in operation, NH 3 is being oxidized to N 2 at the anode electrode.

18 . The electrochemical cell of claim 12 , wherein the electrochemical cell is a direct ammonia fuel cell.

Assignees

• Wisconsin Alumni Res Found

Inventors

• Berry John
• Wallen Christian
• Trenerry Michael
• Brown Tristan
• Park Sungho

Classifications

• C25B1/01

  Products · CPC title

• B01J2531/821

  Ruthenium · CPC title

• C25B11/085

  Organic compound · CPC title

• B01J2231/70

  Oxidation reactions, e.g. epoxidation, (di)hydroxylation, dehydrogenation and analogues · CPC title

• C01B21/02 Primary

  Preparation of nitrogen (by decomposition of ammonia C01B3/047) · CPC title