# US 4,394,228 A · Raney alloy coated cathode for chlor-alkali cells

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- Number: US 4,394,228 A
- Document ID: US4394228A
- Status: Granted
- Kind: A
- Application number: 06/334,058
- Filed: 1981-12-23
- Granted: 1983-07-19
- Earliest claimed: 1980-08-18
- Assignees: Olin Corporation
- Inventors: Thomas J. Gray
- Web page: https://patentgrep.com/patent/US4394228A

## CPC

- C25B 11/091: consisting of at least one catalytic element and at least one catalytic compound; consisting of two or more catalytic elements or catalytic compounds
- C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B)

## Abstract

An improved cathode with a conductive metal core and a Raney-type catalytic surface predominantly derived from an adherent Beta Nickel (NiAl.sub.3) crystalline precursory outer portion of the metal core is disclosed. The precursory outer portion preferably has molybdenum added to give a precursor alloy having the formula Ni.sub.x Mo.sub.1-x Al.sub.3 where x is within the range of from about 5 to about 15 weight percent. Also disclosed is a method of producing a low overvoltage cathode. The method includes the steps of taking a Ni-Mo core or substrate having about 5-20 weight percentage of Mo and coating it with aluminum then heat treating to form a Ni-Mo-Al alloy with mostly Beta Nickel (NiAl.sub.3) structure and then leaching out the Al to produce a Raney surface.

## Claims

### Claim 1

In a process of producing alkali metal hydroxide comprising electrolyzing an aqueous alkali metal chloride brine in an electrolytic cell having an anode, a cathode comprising a substrate with a catalytic surface thereon, said anode being separated from cathode by a synthetic fluorocarbon resin permionic membrane, the improvement wherein
a. said membrane is a member of a class consisting of cationic exchange membranes of hydrophillic phosphonated, sulfonated or carboxylated fluorocarbontelomers; and
b. said cathode surface comprises a Raney nickel alloy, said Raney alloy being predominantly derived from an adherent layer of Ni.sub.x Mo.sub.1-x Al.sub.3 beta structured precursory crystalline surface layer where x is between 0.80 and 0.95.

### Claim 2 (depends on 1)

The process of claim 1 wherein said membrane comprises a sulfonic acid substituted fluorocarbontelomer.

### Claim 3

In an electrolytic cell having an anode, a cathode comprising a substrate with a catalytic surface thereon, and a synthetic fluorocarbon resin permionic membrane therebetween, the improvement wherein:
a. said membrane is a member of a class consisting of cationic exchange membranes of hydrophillic phosphonated, sulfonated or carboxylated fluorocarbontelomers; and
b. said cathode surface comprises a Raney nickel alloy, said Raney alloy being predominantly derived from an adherent layer of Ni.sub.x Mo.sub.1-x Al.sub.3 beta structured precursory crystalline surface layer where x is between 0.80 and 0.95.

### Claim 4 (depends on 3)

The process of claim 3 wherein said membrane comprises a sulfonic acid substituted fluorocarbontelomer.

### Claim 5 (depends on 1)

The process of claim 1 wherein said membrane comprises a carboxylated fluorocarbontelomer.

### Claim 6 (depends on 1)

The process of claim 1 wherein said membrane comprises a phosphonated fluorocarbontelomer.

### Claim 7 (depends on 1)

The process of claim 1 wherein the value of x is between 0.82 and 0.88.

### Claim 8 (depends on 1)

The process of claim 1 wherein said cathode surface layer is on a plate substrate.

### Claim 9 (depends on 1)

The process of claim 1 wherein said cathode surface layer is on an expanded metal substrate.

### Claim 10 (depends on 2)

The process of claim 2 wherein said sulfonated fluorocarbontelomer has been chemically modified by ethylene diamine to convert the surface of said telomer to a perfluorosulfonamide.

### Claim 11 (depends on 3)

The cell of claim 3 wherein said membrane comprises a carboxylated fluorocarbontelomer.

### Claim 12 (depends on 3)

The cell of claim 3 wherein said membrane comprises a phosphonated fluorocarbonetomer.

### Claim 13 (depends on 3)

The cell of claim 3 wherein x is between 0.82 and 0.88.

### Claim 14 (depends on 3)

The cell of claim 3 wherein said cathode surface layer is on a plate substrate.

### Claim 15 (depends on 3)

The cell of claim 3 wherein said cathode surface layer is on an expanded metal substrate.

### Claim 16 (depends on 4)

The cell of claim 4 wherein said sulfonated fluorocarbontelomer has been chemically modified by ethylene diamine to convert the surface of said telomer to a perfluorosulonamide.