Electrolysis cell of alkali solutions

Patent metadata

Field	Value
Publication number	US-2016369412-A1
Application number	US-201414902376-A
Country	US
Kind code	A1
Filing date	Jul 15, 2014
Priority date	Jul 17, 2013
Publication date	Dec 22, 2016
Grant date	—

Abstract

The invention relates to an electrochemical cell partitioned by a cation-exchange membrane suitable for production of high purity hydrogen and oxygen by electrolysis of alkaline solutions comprising a cathode in form of porous web including a platinum or palladium catalyst. The cell can be used as an element of a modular filter-press electrolyser.

First claim

1 . Electrolysis cell partitioned by a cation-exchange membrane into an anodic and a cathodic compartment each provided with means for feeding and for discharging an alkaline solution, said anodic compartment containing an anode suitable for oxygen evolution, said cathodic compartment containing a cathode suitable for hydrogen evolution comprising a porous web in intimate contact with said membrane through a catalytically-activated layer containing at least one noble metal selected between platinum and palladium.

2 . The cell according to claim 1 wherein said cathode suitable for hydrogen evolution comprises a second layer consisting of carbon or metal powders and polymer binders, adjacent said catalytically-activated layer on the side opposite the membrane and having less hydrophilic characteristics with respect to said catalytically-activated layer.

3 . The cell according to claim 1 wherein said cation-exchange membrane is a non-reinforced monolayer sulphonic membrane.

4 . The cell according to claim 1 wherein said cathode is put in electrical contact with said cathodic wall by means of a current collector consisting of a porous metal structure, optionally a nickel or steel foam.

5 . The cell according to claim 1 wherein said anode suitable for oxygen evolution is put in electrical contact with said anodic wall by means of a current collector consisting of a porous metal structure, optionally a nickel or steel foam or mat.

6 . The cell according to claim 1 wherein said anode suitable for oxygen evolution consists of a substrate made of a nickel or steel mesh or expanded or punched sheet, optionally activated with a catalytic coating, in direct contact with said membrane.

7 . Electrolyser of alkali solutions consisting of a modular arrangement of cells according to claim 1 , electrically connected through said anodic and cathodic walls according to a bipolar or monopolar configuration.

8 . Process of electrolysis in a cell according to claim 1 comprising the following simultaneous or sequential steps:
feeding an electrolyte consisting of an alkali metal hydroxide solution to said anodic and cathodic compartments;
connecting said cathodic compartment to the negative pole and said anodic compartment to the positive pole of a power unit, with subsequent supply of direct electrical current;
carrying out cathodic evolution of hydrogen within said catalytically-activated layer and discharging said hydrogen from said cathodic compartment;
carrying out evolution of oxygen on the surface of said anode.

9 . The process according to claim 8 wherein said electrolyte consists of an aqueous solution of caustic soda at 10 to 20% by weight concentration.

Assignees

• Industrie De Nora Spa

Inventors

• Krasovic Julia Lynne

Classifications

• Y02E60/36

  Hydrogen production from non-carbon containing sources, e.g. by water electrolysis · CPC title

• C25B11/035

  Chemistry & Metallurgy · mapped topic

• C25B1/08 Primary

  Chemistry & Metallurgy · mapped topic

• C25B9/10

  Chemistry & Metallurgy · mapped topic

• C25B11/0473

  Chemistry & Metallurgy · mapped topic