Method of forming a Pd—Au alloy layer on a substrate

Patent metadata

Field	Value
Publication number	US-12168199-B2
Application number	US-202217856534-A
Country	US
Kind code	B2
Filing date	Jul 1, 2022
Priority date	Jun 6, 2016
Publication date	Dec 17, 2024
Grant date	Dec 17, 2024

Abstract

A method for preparing a palladium-gold alloy layer on a substrate by electrodepositing said coating surface with an aqueous electroplating solution comprising of an aqueous solution of a soluble palladium compound and a soluble gold complex, wherein the ratio of gold to palladium to in the solution is from 5 to 40 w/w %. Also taught is a substrate such as a vanadium or vanadium alloy gas separation membrane coated with a palladium-gold alloy layer.

First claim

The invention claimed is:

1. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane, comprising a palladium-gold alloy coating on a vanadium or vanadium alloy-based gas separation membrane, the coating having a thickness of between 100 nm and 5 microns and having a composition of from Pd 60 Au 40 to Pd 95 Au 5 ,
wherein the palladium-gold alloy coating has a bulbous and/or cauliflower shaped morphology having a lightness of less than 50, where a lightness of 100 represents the lightest of whites and a lightness of 0 represents the darkest of blacks, measured using a Chroma Meter; and
wherein the palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane has a hydrogen permeability of at least 1×10 −7 mol/m/s/Pa 0.5 at temperatures between 325 to 350° C.

2. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , wherein the palladium-gold alloy coating has a lightness of less than 40 measured using a Chroma Meter.

3. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , wherein the palladium-gold alloy coating has a lightness of less than 35 measured using a Chroma Meter.

4. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , wherein the palladium-gold alloy coating has a lightness of less than 30 measured using a Chroma Meter.

5. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , wherein the palladium-gold alloy has a purity of at least 99.9%.

6. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , wherein the palladium-gold alloy has a purity of at least 99.99%.

7. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , wherein the palladium-gold alloy coating has a thickness of from 100 nm to 1 micron.

8. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , wherein the palladium-gold alloy coating has a thickness of from 200 to 500 nm.

9. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , wherein the palladium-gold alloy coating has a composition of from Pd 70 Au 30 to Pd 90 Au 10 .

10. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , wherein the palladium-gold alloy coating has a composition of Pd 70 Au 30 at %.

11. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , wherein the palladium-gold alloy coating has a 5A classification in accordance to ASTM D3359-97.

12. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , having a hydrogen permeability of 1 to 2.5×10 −7 mol/m/s/Pa 0.5 at temperatures between 325 to 350° C.

13. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , having a steady state H 2 permeability in 20 ppm H 2 S of 1 to 50×10 −8 mol/m/s/Pa 0.5 at temperatures between 325 to 350° C.

14. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 1 , comprising a tubular gas separation membrane.

15. A palladium-gold alloy coated vanadium or vanadium alloy-based gas separation membrane according to claim 14 , wherein the tubular gas separation membrane comprises a tube having an outer diameter of between 2 to 25 mm.

16. A method of preparing a palladium-gold alloy layer on a vanadium or vanadium alloy-based gas separation membrane comprising:
providing a nonporous vanadium or vanadium alloy-based gas separation membrane having a coating surface; and
electrodepositing said coating surface with an aqueous electroplating solution comprising a soluble palladium compound and a soluble gold complex,
wherein the ratio of gold to palladium in the solution is from 5 to 40%, said electrodepositing is conducted for a period of time sufficient to simultaneously deposit both palladium and gold as a layer of palladium-gold alloy on the coating surface from the aqueous electroplating solution, wherein the said layer has a surface roughness; and
wherein the surface roughness of said layer of palladium-gold alloy deposited on said coating surface is manipulated through at least one of: temperature of the aqueous electroplating solution, current density, or agitation of the aqueous electroplating solution, to create an outer surface of said layer of palladium-gold alloy having a lightness of less than 50 measured using a Chroma Meter,
thereby producing a nonporous vanadium or vanadium alloy-based gas separation membrane coated with said palladium-gold alloy layer.

17. The method according to claim 16 , wherein the palladium compound is palladium diamino dinitrite, palladium sulfate, palladium phosphate, a palladium organo sulfonate or a palladium organo phosphonate, and wherein the gold complex comprises potassium gold cyanide or sodium gold cyanide.

Assignees

• Commw Scient Ind Res Org

Inventors

• Langley Matthew
• Viano David
• Dolan Michael

Classifications

• C25D3/567 Primary

  containing more than 50% by weight of platinum group metals · CPC title

• B01D71/02231

  Palladium · CPC title

• B01D71/0221

  Group 4 or 5 metals · CPC title

• B01D67/0069

  by deposition from the liquid phase, e.g. electrochemical deposition (B01D67/0046 takes precedence) · CPC title

• B01D69/04

  Tubular membranes · CPC title