An electrolytic composition and cathode for the nitrogen reduction reaction

Patent metadata

Field	Value
Publication number	US-2021238756-A1
Application number	US-201916972160-A
Country	US
Kind code	A1
Filing date	Jun 27, 2019
Priority date	Jun 28, 2018
Publication date	Aug 5, 2021
Grant date	—

Abstract

The invention provides a cathode for the nitrogen reduction reaction, comprising an electrically conductive substrate and an electrocatalytic composition on the substrate, wherein the electrocatalytic composition comprises: a support material present in one or more crystalline phases; and metallic clusters dispersed on the support material, the metallic clusters comprising at least one metal selected from ruthenium, iron, rhodium, iridium and molybdenum, wherein at least 80 mass % of the support material is present in a semiconductive crystalline phase having a conduction band minimum energy below (more positive than) −0.3 V relative to the normal hydrogen electrode (NHE).

First claim

1 . A cathode for the nitrogen reduction reaction, comprising an electrically conductive substrate and an electrocatalytic composition on the substrate, wherein the electrocatalytic composition comprises:
a support material present in one or more crystalline phases; and metallic clusters dispersed on the support material, the metallic clusters comprising at least one metal selected from ruthenium, iron, rhodium, iridium and molybdenum, wherein at least 80 mass % of the support material is present in a semiconductive crystalline phase having a conduction band minimum energy below (more positive than) −0.3 V relative to the normal hydrogen electrode (NHE).

2 . (canceled)

3 . (canceled)

4 . The cathode according to claim 1 , wherein the semiconductive crystalline phase has a conduction band minimum energy below (more positive than) 0 V relative to the normal hydrogen electrode (NHE).

5 . The cathode according to claim 1 , wherein the support material comprises at least one selected from molybdenum disulphide (MoS 2 ), ferric oxide (Fe 2 O 3 ) and titanium dioxide (TiO 2 ).

6 . The cathode according to claim 1 , wherein the metallic clusters have an average cluster size of from 1 to 10 nm.

7 . The cathode according to claim 1 , wherein the semiconductive crystalline phase is a 2D-crystalline phase.

8 . The cathode according to claim 7 , wherein the metallic clusters are at least partially intercalated between layers of the 2D-crystalline phase.

9 . The cathode according to claim 7 , wherein the support material comprises molybdenum disulphide (MoS 2 ) and the 2D-crystalline phase comprises 2H—MoS 2 .

10 . (canceled)

11 . A method of reducing dinitrogen to ammonia, the method comprising:
contacting an electrocatalytic composition with dinitrogen and an electrolyte comprising a source of hydrogen; and applying a potential at the electrocatalytic composition sufficient to reduce the dinitrogen and the source of hydrogen on the electrocatalytic composition to form ammonia, wherein the electrocatalytic composition comprises: a support material present in one or more crystalline phases; and metallic clusters dispersed on the support material, the metallic clusters comprising at least one metal selected from ruthenium, iron, rhodium, iridium and molybdenum, wherein at least 80 mass % of the support material is present in a semiconductive crystalline phase having a conduction band minimum energy below (more positive than) −0.3 V relative to the normal hydrogen electrode (NHE).

12 . (canceled)

13 . (canceled)

14 . The method according to claim 11 , wherein the semiconductive crystalline phase has a conduction band minimum energy below (more positive than) 0 V relative to the normal hydrogen electrode (NHE).

15 . The method according to claim 11 , wherein the support material comprises at least one selected from molybdenum disulphide (MoS 2 ), ferric oxide (Fe 2 O 3 ) and titanium dioxide (TiO 2 ).

16 . (canceled)

17 . The method according to claim 11 , wherein the semiconductive crystalline phase is a 2D-crystalline phase.

18 . The method according to claim 17 , wherein the metallic clusters are at least partially intercalated between layers of the 2D-crystalline phase.

19 . (canceled)

20 . The method according to claim 11 , wherein the potential is in the range of −50 mV to −500 mV relative to the reversible hydrogen electrode (RHE).

21 . The method according to claim 11 , further comprising providing or replenishing the source of hydrogen in the electrolyte by oxidising a hydrogen-containing species at an anode in electrochemical communication with the electrolyte.

22 . The method according to claim 11 , further comprising recovering a product stream comprising the ammonia and recycling dihydrogen (H 2 ) present in the product stream for contact with the electrocatalytic composition and/or for oxidation at an anode in electrochemical communication with the electrolyte.

23 . The method according to claim 11 , wherein the electrolyte comprises an aprotic liquid, an ionic liquid or an ionic liquid dissolved in an aprotic liquid.

24 . An electrocatalytic composition for the nitrogen reduction reaction, comprising:
a support material present in one or more crystalline phases; and metallic clusters dispersed on the support material, the metallic clusters comprising at least one metal selected from ruthenium, iron, rhodium, iridium and molybdenum, wherein at least 80 mass % of the support material is present in a semiconductive 2D-crystalline phase having a conduction band minimum energy below (more positive than) −0.3 V relative to the normal hydrogen electrode (NHE).

25 . (canceled)

26 . (canceled)

27 . (canceled)

28 . The electrocatalytic composition according to claim 24 , wherein the metallic clusters have an average cluster size of from 1 to 10 nm.

29 . The electrocatalytic composition according to claim 24 , wherein the metallic clusters are at least partially intercalated between layers of the 2D-crystalline phase.

30 . The electrocatalytic composition according to claim 24 , wherein the support material comprises molybdenum disulphide (MoS 2 ) and the 2D-crystalline phase comprises 2H—MoS 2 .

31 . (canceled)

32 . (canceled)

33 . (canceled)

34 . (canceled)

35 . (canceled)

36 . (canceled)

37 . (canceled)

Assignees

• Univ Monash

Inventors

• Macfarlane Douglas R
• Suryanto Bryan Harry Rahmat
• Wang Dabin
• Du Hoang-Long

Classifications

• C25B1/27

  Ammonia · CPC title

• Y02P20/52

  using catalysts, e.g. selective catalysts · CPC title

• B01J23/28

  Molybdenum · CPC title

• C25B11/081

  the element being a noble metal · CPC title

• B01J23/468

  Iridium · CPC title