Method for electrochemically producing alkane dicarboxylic acids by means of a ring-opening oxidation using a doped Ni(O)OH foam electrode

Patent metadata

Field	Value
Publication number	US-11976373-B2
Application number	US-202118001079-A
Country	US
Kind code	B2
Filing date	May 26, 2021
Priority date	Jun 10, 2020
Publication date	May 7, 2024
Grant date	May 7, 2024

Abstract

A method for the electrochemical preparation of alkanedicarboxylic acids involves a ring-opening oxidation with a doped Ni(O)OH foam electrode in an aqueous alkaline solution.

First claim

The invention claimed is:

1. A method for the preparation of alkanedicarboxylic acids, the method comprising:
oxidizing a cyclic reactant in a ring-opening oxidation in an aqueous alkaline solution, wherein the oxidation is carried out at an Ni(O)OH foam electrode doped with at least one element of main group 5 and/or 6, according to Scheme (I):

wherein represents a single or double bond, R accordingly being present or not,
wherein R is hydrogen or an acyl radical, wherein the acyl radical is a radical of an aliphatic monocarboxylic acid having 2 to 8 carbon atoms, and
wherein A is a hydrocarbon having 4 to 30 carbon atoms, in which all ring carbon atoms of A in the cyclic reactant of scheme (I) bear at least one hydrogen substituent, and
wherein the Ni(O)OH foam electrode comprises 2 to 10% by weight of phosphorus, the phosphorus as an element and based on a metal mass of the Ni(O)OH foam electrode.

2. The method according to claim 1 , wherein the Ni(O)OH foam electrode is doped with at least one selected from the group consisting of phosphorus, arsenic, selenium, and sulfur.

3. The method according to claim 1 , wherein the Ni(O)OH foam electrode comprises 3 to 9% by weight of the phosphorus, the phosphorus as an element and based on the metal mass of the electrode.

4. The method according to claim 1 , wherein the Ni(O)OH foam electrode is two or more millimeters thick.

5. The method according to claim 1 , wherein the Ni(O)OH foam electrode comprises nickel as metal.

6. The method according to claim 5 , wherein the Ni(O)OH foam electrode comprises the nickel in an amount of at least 80% by weight.

7. The method according to claim 1 , wherein the aqueous alkaline solution comprises up to 30% by volume of a cosolvent.

8. The method according to claim 1 , wherein an alkaline additive in the aqueous alkaline solution is lithium hydroxide, sodium hydroxide, or potassium hydroxide.

9. The method according to claim 8 , wherein a concentration of the alkaline additive is 0.5 to 2 mol/1, based on the aqueous alkaline solution.

10. The method according to claim 8 , wherein no further anions of bases are present in the aqueous alkaline solution other than the alkaline additive.

11. The method according to claim 1 , wherein in scheme (I) when R=hydrogen and is a single bond, a concentration of cycloalkanols is 0.06 to 0.5 mol/1.

12. The method according to claim 11 , wherein the concentration of cycloalkanols is 0.09 to 0.11 mol/1.

13. The method according to claim 1 , wherein the ring-opening oxidation is according to Scheme (II):

wherein R 1 , R 2 , R 3 are the same or different, and are hydrogen or alkyl radicals having 1 to 8 carbon atoms, linear or branched, in which at least one of R 1 , R 2 , R 3 is an alkyl radical.

14. The method according to claim 13 , wherein only one of R 1 , R 2 , R 3 is an alkyl radical having 1 to 4 carbon atoms.

15. The method according to claim 13 , wherein R 1 and R 3 are hydrogen and R 2 is an alkyl radical having 1 to 4 carbon atoms.

16. The method according to claim 1 , wherein the method is carried out at a current density of 2 to 10 mA/cm 2 , an area referring to a geometric area without consideration of inner surface area of the foam.

17. The method according to claim 1 , wherein the oxidizing comprises electrolysis carried out in a batch electrolytic cell or in a continuous flow electrolytic cell.

18. The method according to claim 17 , wherein the oxidizing comprises electrolysis carried out in the continuous flow electrolytic cell.

19. The method according to claim 1 , wherein a cathode material is stainless steel, platinum, nickel, or a mixture thereof.

20. The method according to claim 1 , wherein the oxidizing comprises electrolysis carried out at a temperature of 20-70° C.

Assignees

• Evonik Operations Gmbh

Inventors

• Weinelt Frank
• Baumann Franz-Erich
• Waldvogel Siegfried R
• Rauen Anna-Lisa

Classifications

• C25B3/23 Primary

  Oxidation (halogenation C25B3/27) · CPC title

• C25B3/07

  Oxygen containing compounds · CPC title

• C25B9/15

  Flow-through cells · CPC title

• C25B11/031

  Porous electrodes · CPC title

• C25B11/047

  Ceramics · CPC title