Hydrogen separation membrane

Patent metadata

Field	Value
Publication number	US-11383207-B2
Application number	US-201816958835-A
Country	US
Kind code	B2
Filing date	Dec 26, 2018
Priority date	Dec 28, 2017
Publication date	Jul 12, 2022
Grant date	Jul 12, 2022

Abstract

The present invention pertains to a polycrystalline membrane containing metal nitride particles represented by the general formula MNx (where M is a metal element in which the Fermi energy is in a position higher than −4.4 eV vs L.V. and x is the range over which a rock salt-type structure can be assumed), in which the crystallite size determined by transmission electron microscopy is 10 nm or less, at least some of the crystallites have rock salt-type structure, and the crystallites exhibit (111) orientation but substantially do not exhibit (100) orientation. The present invention also pertains to a method for manufacturing a polycrystalline membrane, comprising forming, by sputtering, a polycrystalline membrane on a substrate having a temperature of less than 200° C., the polycrystalline membrane being represented by the general formula MNx and being such that at least some crystallites have a rock salt structure and the crystallites exhibit (111) orientation but essentially do not exhibit (100) orientation. The present invention provides a hydrogen-permeable TiNx microparticle membrane exhibiting a higher mixed hydride ion (H−)-electron conduction.

First claim

The invention claimed is:

1. A membrane for hydrogen separation comprising a polycrystalline substance membrane comprising particles of a metal nitride represented by the general formula MNx, wherein M is a metal element of which metal nitride exhibits Fermi energy of higher than −4.4 eV vs L.V., and x is within the range where rock salt structure is adopted, wherein crystallite size determined by transmission electron microscopy observation is 5 nm or less, at least a part of the crystallite has rock salt structure, the crystallite exhibits (111) orientation but substantially no (100) orientation.

2. A method for production of the membrane for hydrogen separation according to claim 1 , comprising forming by sputtering onto a substrate at a temperature of less than 20° C., a polycrystalline substance membrane comprising metal nitride particles represented by the general formula MNx, wherein M is a metal element of which metal nitride exhibits Fermi energy of higher than −4.4 eV vs V.L. and x is within the range where rock salt structure is adopted, at least a portion of crystallite has rock salt structure, and the crystallite exhibits (111) orientation but substantially no (100) orientation.

3. The method for production according to claim 2 , wherein the substrate is a porous substance.

4. The membrane for hydrogen separation according to claim 1 , wherein M is at least one metal selected from the group consisting of Ti, Hf, Ta, Mo, Cr, V and Zr.

5. The membrane for hydrogen separation according to claim 1 , wherein M is Ti and x is 0.5 or more and 1.0 or less.

6. The membrane for hydrogen separation according to claim 1 , wherein the polycrystalline substance membrane comprises hydride ion (H − ).

7. The membrane for hydrogen separation according to claim 1 , wherein the membrane comprises the polycrystalline substance membrane on a substrate.

8. The membrane for hydrogen separation according to claim 7 , wherein the substrate is a porous alumina substrate.

9. The membrane for hydrogen separation according to claim 8 , wherein the porous alumina substrate is a porous alumina substrate surface modified with a mesoporous γ Al 2 O 3 layer.

10. The membrane for hydrogen separation according to claim 1 , wherein the polycrystalline substance membrane has a thickness of from 100 nm to 5000 nm.

11. The membrane for hydrogen separation according to claim 5 , wherein atomic ratio O/Ti of the polycrystalline substance membrane is 0.1 or less.

12. The method for production according to claim 2 , wherein the substrate is a porous alumina substrate.

13. The method for production according to claim 12 , wherein the porous alumina substrate is a porous alumina substrate surface modified with a mesoporous γ Al 2 O 3 layer.

14. A method for separation of hydrogen from a gas mixture comprising:
exposing the gas mixture comprising hydrogen to a polycrystalline substance membrane comprising particles of a metal nitride represented by the general formula MNx, wherein MN is a metal nitride of which Fermi energy is higher than −4.4 eV vs L.V., and x is within the range where rock salt structure is adopted, wherein crystallite size determined by transmission electron microscopy observation is 5 nm or less, at least a part of the crystallite has rock salt structure, the crystallite exhibits (111) orientation but substantially no (100) orientation.

15. The method for separation of hydrogen according to claim 14 , wherein M is at least one metal selected from the group consisting of Ti, Hf, Ta, Mo, Cr, V and Zr.

16. The method for separation of hydrogen according to claim 14 , wherein M is Ti and x is 0.5 or more and 1.0 or less.

17. The method for separation of hydrogen according to claim 14 , wherein the polycrystalline substance membrane comprises hydride ion (H − ).

18. The method for separation of hydrogen according to claim 14 , wherein the membrane comprises the polycrystalline substance membrane on a substrate.

Assignees

• Univ Hokkaido Nat Univ Corp

Inventors

• Aoki Yoshitaka
• KURA Chiharu
• Habazaki Hiroki

Classifications

• B01D71/022 Primary

  Metals · CPC title

• B01D71/0281

  Zeolites · CPC title

• B01D69/108

  Inorganic support material · CPC title

• B01D71/025

  Aluminium oxide · CPC title

• B01D53/228

  characterised by specific membranes · CPC title