Low-temperature method for electrochemical conversion of carbon dioxide to carbon

Patent metadata

Field	Value
Publication number	US-2025109507-A1
Application number	US-202418899060-A
Country	US
Kind code	A1
Filing date	Sep 27, 2024
Priority date	Sep 29, 2023
Publication date	Apr 3, 2025
Grant date	—

Abstract

A method for converting carbon dioxide to carbon (e.g., graphite, graphene, or amorphous porous carbon), the method comprising passing the carbon dioxide through a molten anhydrous salt maintained at a temperature within a range of 400° C.-800° C. while the molten anhydrous salt is in contact with a cathode and an anode that are electrically interconnected to impart a voltage to the molten anhydrous salt, wherein the cathode has a metal composition comprising at least one of nickel, iron, and cobalt, wherein the voltage is within a range of 2 V to 3.5 V, and wherein the temperature and voltage are applied for a period of time of 5 minutes to 10 hours (or, e.g., 0.1-10 or 1-10 hours) to result in conversion of the carbon dioxide to carbon.

First claim

What is claimed is:

1 . A method for converting carbon dioxide to carbon, the method comprising passing the carbon dioxide through a molten anhydrous salt maintained at a temperature within a range of 400° C.-800° C. while the molten anhydrous salt is in contact with a cathode and an anode that are electrically interconnected to impart a voltage to the molten anhydrous salt, wherein the cathode has a metal composition comprising at least one of nickel, iron, and cobalt, wherein the voltage is within a range of 2 V to 3.5 V, and wherein the temperature and voltage are applied for a period of time of 5 minutes to 10 hours to result in conversion of the carbon dioxide to carbon.

2 . The method of claim 1 , wherein the molten anhydrous salt comprises a lithium salt or lithium oxide and at least one salt selected from non-lithium alkali metal salts and alkaline earth metal salts, provided that the molten anhydrous salt has a melting point within a range of 400° C.-800° C.

3 . The method of claim 1 , wherein the molten anhydrous salt comprises a lithium salt or lithium oxide and at least one salt selected from non-lithium alkali metal salts and alkaline earth metal salts and at least one metal hydroxide selected from sodium hydroxide and potassium hydroxide, provided that the molten anhydrous salt has a melting point within a range of 400° C.-800° C.

4 . The method of claim 1 , wherein the molten anhydrous salt comprises lithium carbonate and at least one salt selected from non-lithium alkali metal salts and alkaline earth metal salts, provided that the molten anhydrous salt has a melting point within a range of 400° C.-800° C.

5 . The method of claim 1 , wherein the molten anhydrous salt comprises lithium carbonate and at least one salt selected from sodium carbonate and potassium carbonate.

6 . The method of claim 1 , wherein the molten anhydrous salt comprises lithium carbonate, sodium carbonate, and potassium carbonate.

7 . The method of claim 1 , wherein the molten anhydrous salt is maintained at a temperature within a range of 400° C.-700° C.

8 . The method of claim 1 , wherein the molten anhydrous salt is maintained at a temperature within a range of 400° C.-600° C.

9 . The method of claim 1 , wherein the molten anhydrous salt is maintained at a temperature within a range of 400° C.-550° C.

10 . The method of claim 1 , wherein the cathode is a porous cathode.

11 . The method of claim 10 , wherein the cathode is a nickel foam cathode.

12 . The method of claim 10 , wherein the carbon produced by the method is substantially graphitic, with a degree of graphitization of at least 0.95.

13 . The method of claim 10 , wherein the molten anhydrous salt is maintained at a temperature within a range of 500° C.-800° C. at a voltage within a range of 2.5 V to 3.5 V and the carbon produced by the method is substantially graphitic, with a degree of graphitization of at least 0.95.

14 . The method of claim 13 , wherein the voltage is within a range of 2.5 V to 3.0 V.

15 . The method of claim 13 , wherein the temperature and voltage are maintained for a period of time of 0.1-3.5 hours to result in conversion of the carbon dioxide to the substantially graphitic carbon.

16 . The method of claim 10 , wherein the molten anhydrous salt is maintained at a temperature within a range of 400° C.-500° C. and the carbon produced by the method comprises graphene.

17 . The method of claim 1 , wherein the cathode is a nickel or steel plate, and the carbon produced by the method is substantially amorphous carbon.

18 . The method of claim 17 , wherein the substantially amorphous carbon is porous carbon.

19 . The method of claim 18 , wherein the porous carbon comprises microporous or mesoporous carbon.

20 . The method of claim 1 , wherein the molten anhydrous salt is maintained at a temperature within a range of 500° C.-700° C. and the carbon produced by the method is substantially amorphous carbon.

21 . The method of claim 20 , wherein the temperature and voltage are maintained for a period of time of 3-10 hours to result in conversion of the carbon dioxide to the substantially amorphous carbon.

22 . The method of claim 20 , wherein the temperature and voltage are maintained for a period of time of 4-10 hours to result in conversion of the carbon dioxide to the substantially amorphous carbon.

23 . The method of claim 20 , wherein the cathode is a nickel or steel plate.

24 . The method of claim 20 , wherein the substantially amorphous carbon is porous carbon.

25 . The method of claim 24 , wherein the porous carbon comprises microporous or mesoporous carbon.

Assignees

• Ut Battelle Llc

Inventors

• Prasad Thapaliya Bishnu
• Mahurin Shannon M
• Dai Sheng
• Sun Xiao-Guang
• Ivanov Aleksandr

Classifications

• C25B1/00

  Electrolytic production of inorganic compounds or non-metals · CPC title

• C25B1/135 Primary

  Carbon · CPC title

• C25B9/09 Primary

  Fused bath cells · CPC title