Anode for electrolytic evolution of chlorine

Patent metadata

Field	Value
Publication number	US-12448693-B2
Application number	US-201916973245-A
Country	US
Kind code	B2
Filing date	Jun 13, 2019
Priority date	Jun 21, 2018
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

The invention relates to a process for obtaining a electrode usable as a anode in electrolytic cells for the production of chlorine. The electrode thus obtained comprises a catalytic layer containing oxides of tin, ruthenium, iridium and titanium applied to a substrate of a valve metal.

First claim

The invention claimed is:

1. A method for the production of an electrode comprising the following steps:
a) applying to a valve metal substrate an acetic solution consisting of hydroxyacetochloride complexes of iridium, ruthenium, tin and titanium, subsequent drying at 50-60° C. and thermal decomposition at 450-600° C. for a time of 5 to 30 minutes until reaching a specific noble metal loading expressed as the sum of iridium and ruthenium between 0.4 and 1 g/m 2 ; followed by
b) repeating step a) until obtaining a catalytic coating with a specific noble metal loading of 6 to 12 g/m 2 ; and thereafter
c) heat treating at 450-600° C. for a time of 50 to 200 minutes.

2. The method according to claim 1 , wherein said acetic solution contains 5-40% of tin, 3.6-15% of iridium, 18-40% of ruthenium and 30-70% of titanium, in molar percentage referred to the elements.

3. A method for the production of an electrode for gas evolution in electrolytic processes comprising the following steps:
a) applying to a valve metal substrate an acetic solution consisting of hydroxyacetochloride complexes of iridium, ruthenium, tin and titanium complexes containing 5-40% of tin, 3.6-15% of iridium, 18-40% of ruthenium and 30-70% of titanium, in molar percentage referred to the elements; subsequent drying at 50-60° C. and thermal decomposition at 450-600° C. for a time of 5 to 30 minutes until reaching a specific noble metal loading expressed as the sum of iridium and ruthenium of 0.4 to 1 g/m 2 ; followed by
b) repeating step a) until obtaining a catalytic coating with a specific noble metal loading of 6 to 12 g/m 2 ; and thereafter
c) heat treating at 450-600° C. for a time of 50 to 200 minutes.

4. The method according to claim 3 , wherein said acetic solution contains 6-30% of tin, 3.7-12% of iridium, 20-30% of ruthenium and 50-70% of titanium, in molar percentage referred to the elements.

5. The method according to claim 1 , wherein the temperature of said thermal decomposition in step a) and heat treatment in step c) is between 48° and 550° C.

6. A method for the production of an electrode comprising the following steps:
a) applying to a valve metal substrate an acetic solution consisting of hydroxyacetochloride complexes of iridium, ruthenium, tin and titanium, subsequent drying at 50-60° C. and thermal decomposition at 450-600° C. for a time of 5 to 30 minutes until reaching a specific noble metal loading expressed as the sum of iridium and ruthenium between 0.4 and 1 g/m 2 ; followed by
b) repeating step a) until obtaining a catalytic coating with a specific noble metal loading of 6 to 12 g/m 2 ; and thereafter
c) heat treating at 450-600° C. for a time of 50 to 200 minutes, thereby obtaining the electrode comprising the valve metal substrate and the catalytic coating containing 5-40% of tin, 3.6-15% of iridium, 18-40% of ruthenium and 30-70% of titanium, in the form of metals or their oxides in molar percentage referred to the elements.

7. The method according to claim 1 , wherein said acetic solution contains 6-30% of tin, 3.7-12% of iridium, 20-30% of ruthenium and 50-70% of titanium, in molar percentage referred to the elements.

8. The method according to claim 1 , wherein said acetic solution contains 8-18% of tin, 4-10% of iridium, 18-36% of ruthenium and 45-65% of titanium, in molar percentage referred to the elements.

9. The method according to claim 3 , wherein said acetic solution contains 8-18% of tin, 4-10% of iridium, 18-36% of ruthenium and 45-65% of titanium, in molar percentage referred to the elements.

Assignees

• Industrie De Nora Spa

Inventors

• Gargiulo Alice
• Calderara Alice
• Iacopetti Luciano

Classifications

• C23C18/02

  by thermal decomposition · CPC title

• C23C18/1225

  Deposition of multilayers of inorganic material · CPC title

• C25B13/00

  Diaphragms; Spacing elements · CPC title

• C25B1/26

  Chlorine; Compounds thereof (by simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine C25B1/34) · CPC title

• C25B9/23

  comprising ion-exchange membranes in or on which electrode material is embedded · CPC title