Method of forming a Pd—Au alloy layer on a substrate
AssigneeCommonwealth Scientific and Industrial Research Organisation
InventorsMatthew Langley, David Viano, Michael Dolan
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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.
Claims17
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 Pd60Au40 to Pd95Au5,
- 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/Pa0.5 at temperatures between 325 to 350° C.
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.
Dependencies are inferred from the claim text.