Membrane, membrane electrode assembly, and water electrolyzer including the same

Patent metadata

Field	Value
Publication number	US-11560632-B2
Application number	US-201916586574-A
Country	US
Kind code	B2
Filing date	Sep 27, 2019
Priority date	Sep 27, 2018
Publication date	Jan 24, 2023
Grant date	Jan 24, 2023

Abstract

A water electrolyzer comprises a membrane, a cathode and an anode. The membrane comprises a first membrane layer comprising a first ion-conductive polymer, a second membrane layer comprising a second ion-conductive polymer, and a platinized nanostructured layer disposed between the first layer and the second layer. The platinized nanostructured layer comprises close-packed whiskers having at least one of platinum or platinum oxide disposed thereon. The cathode is disposed on the membrane and comprises a first catalyst consisting essentially of both metallic Pt and Pt oxide. The anode is disposed on the opposite surface of the membrane and comprises a second catalyst comprising at least 95 percent by weight of collectively metallic Ir and Ir oxide, calculated as elemental Ir, based on the total weight of the second catalyst, wherein at least one of metallic Ir or Ir oxide is present. Membranes and methods of making them are also disclosed.

First claim

What is claimed is:

1. A water electrolyzer comprising:
a membrane having first and second opposed major surfaces and comprising:
a first membrane layer comprising a first ion-conductive polymer;
a second membrane layer comprising a second ion-conductive polymer; and
a first platinized nanostructured layer disposed between the first layer and the second layer, wherein the first platinized nanostructured layer comprises close-packed whiskers having at least one of platinum or platinum oxide disposed thereon;

a cathode disposed on the first major surface of the membrane, the cathode comprising a first catalyst consisting essentially of either or both of metallic platinum and platinum oxide; and
an anode disposed on the second major surface of the membrane, the anode comprising a second catalyst, the second catalyst comprising at least 95 percent by weight of collectively metallic iridium and iridium oxide, calculated as elemental iridium, based on the total weight of the second catalyst, wherein at least one of metallic iridium or iridium oxide is present, wherein the membrane does not further comprise a third membrane layer comprising a third ion-conductive polymer, wherein the membrane does not further comprise a second platinized nanostructured layer disposed between the second membrane layer and the third membrane layer, and wherein the first and second membrane layers are unitary.

2. The water electrolyzer of claim 1 , wherein the first platinized nanostructured layer has a thickness of 0.05 micrometer to 0.5 micrometer.

3. The water electrolyzer of claim 1 , wherein the second catalyst consists essentially of at least one of metallic iridium or iridium oxide.

4. The water electrolyzer of claim 1 , wherein the second catalyst further comprises at least one of metallic platinum or platinum oxide.

5. The water electrolyzer of claim 1 , wherein the second catalyst consists essentially of at least one of metallic platinum or platinum oxide and at least one of metallic iridium or iridium oxide.

6. The water electrolyzer of claim 5 , wherein the at least one of metallic iridium or iridium oxide and at least one of metallic platinum or platinum oxide have a collective weight ratio, calculated as elemental iridium and platinum, respectively, of at least 20:1 iridium to platinum.

7. The water electrolyzer of claim 1 , wherein the at least one of metallic iridium or iridium oxide of the second catalyst collectively has an areal density of at least 0.01 mg/cm 2 .

8. The water electrolyzer of claim 1 , wherein the membrane further comprises polymer electrolyte.

9. The water electrolyzer of claim 8 , wherein the polymer electrolyte is at least one of a perfluorosulfonic acid, a perfluorosulfonimide, or a perfluorosulfonimide sulfonic acid.

10. The water electrolyzer of claim 1 , wherein the at least one of metallic platinum or platinum oxide is collectively present in the membrane at a concentration in a range from 0.05 mg/cm 3 to 100 mg/cm 3 .

11. The water electrolyzer of claim 1 , wherein the at least one of metallic platinum or platinum oxide is distributed throughout the membrane.

12. A method of generating hydrogen and oxygen from water, the method comprising:
providing a water electrolyzer according to claim 1 ;
providing water in contact with the anode; and
providing an electrical current with sufficient potential difference across the membrane to convert at least a portion of the water to hydrogen and oxygen on the cathode and anode, respectively.

Assignees

• 3M Innovative Properties Company

Inventors

• Park Jiyoung
• Lewinski Krzysztof A
• Luopa Sean M
• Steinbach Andrew J L

Classifications

• C25B11/081

  the element being a noble metal · CPC title

• C25B9/73

  of the filter-press type · CPC title

• C25B13/08 Primary

  based on organic materials · CPC title

• C25B1/04 Primary

  by electrolysis of water · CPC title

• C25B9/23

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