Method for the treatment of a metal substrate for the preparation of electrodes

Patent metadata

Field	Value
Publication number	US-2023151503-A1
Application number	US-202117906429-A
Country	US
Kind code	A1
Filing date	Mar 23, 2021
Priority date	Mar 24, 2020
Publication date	May 18, 2023
Grant date	—

Abstract

A method for surface treatment of a metal substrate, suitable for use as electrode support in electrochemical processes by: (a) immersion of the metal substrate and of at least one counter electrode in an electrolyte selected from hydrochloric acid, nitric acid, boric acid or sulfuric acid at a weight concentration of between 10-40%; (b) application of an anodic current density to the metal substrate of between 0.1 and 30 A/dm2 for a time of between 0.5 and 120 minutes. An electrode for gas evolution in electrochemical processes obtained from a correspondingly treated substrate.

First claim

1 . A method for surface treatment of a metal substrate selected from nickel or nickel alloy, suitable for use as electrode support in electrochemical processes, comprising the following steps:
(a) immersing said metal substrate and at least one counter electrode in an electrolyte selected from hydrochloric acid, nitric acid, boric acid or sulfuric acid at a weight concentration of between 10-40%; (b) applying an anodic current density to said metal substrate between 0.1 and 30 A/dm 2 for a time between 0.5 and 120 minutes.

2 . The method according claim 1 wherein said metal substrate is a mesh or a punched or expanded sheet.

3 . The method according to claim 1 wherein said metal substrate has a thickness below 1.2 mm.

4 . The method according to claim 3 wherein said metal substrate has a thickness equal to or less than 0.5 mm.

5 . (canceled)

6 . The method according to claim 1 wherein the applied anodic current density is between 5 and 10 A/dm 2 .

7 . The method according to claim 6 wherein the application time of the anodic current density is between 2 and 10 minutes.

8 . The method according to claim 1 wherein the weight concentration of said electrolyte is between 15-30%.

9 . The method according to claim 1 wherein the metal substrate is nickel or nickel alloy comprising a further step (c) subsequent to step (b) of nickel electrodeposition comprising the addition to said electrolyte of a nickel salt in a concentration by weight between 150 and 300 g/l and subsequent application of a cathodic current density to said metal substrate between 0.1 and 3 A/dm 2 for a time between 0.5 and 120 minutes at a temperature between 15 and 70° C.

10 . A method for manufacturing an electrode for gas evolution in electrochemical processes, comprising the following steps:
treating a metal substrate with the method of claim 1 , and applying a catalytic coating comprising one or more noble or alloy metals or their oxides and/or one or more metals belonging to the rare earth group or their oxides, to said treated metal substrate.

11 . An electrode for gas evolution in electrochemical processes comprising a metal substrate, selected from nickel or nickel alloy, prepared according to the method described in claim 1 , said metal substrate having a degree of homogeneity of the roughness profile, expressed as the mean square deviation Ra values, of less than 25%, and a catalytic coating comprising one or more noble or alloy metals or their oxides and/or one or more metals belonging to the rare earth group or their oxides.

12 . (canceled)

13 . An electrode for gas evolution in electrochemical processes comprising a metal substrate, selected from nickel or nickel alloy, prepared according to the method described in claim 9 , comprising a layer of nickel electrodeposited directly on the metal substrate and a catalytic coating comprising one or more metals or alloys or their oxides and/or one or more metals belonging to the group of rare earths or their oxides.

14 . A cell for the electrolysis of water or for the electrolysis of alkali chloride solutions comprising an anodic compartment and a cathodic compartment separated by an ion-exchange membrane or by a diaphragm, wherein the cathodic compartment is equipped with an electrode according to claim 11 .

Assignees

• Industrie De Nora Spa

Inventors

• Calderara Alice
• Brichese Marianna

Classifications

• C25B11/061

  Metal or alloy · CPC title

• C25B11/03 Primary

  perforated or foraminous · CPC title

• C25B9/19

  with diaphragms · CPC title

• C23C18/08

  characterised by the deposition of metallic material · CPC title

• C25B11/093 Primary

  at least one noble metal or noble metal oxide and at least one non-noble metal oxide · CPC title