Sciencemadness Discussion Board

nickle hydroxide cathodes

beastmaster - 10-11-2010 at 10:26

I am new to electrochemisty. I was going to venture into it and do my first experiment and try to make acitonitrile from analine. It looked straight forward enough. It calls for a nickle hydroxide cathode. Thats where my first problem has developed.
I see they are common in NiCd batteries but no one seem to sell an anode or cathode by its self. I have read several methods for making my own but because of the toxicity of nickel hydroxide I'ed rather not work with it.
I read where nickel hydroxide will form on a nickel cathode in a strong solution of NaOh. Is this a possible route? I use the search but found no info on this. Any help would be appropriated Thank you Beastmaster.

not_important - 10-11-2010 at 13:03

What are "acitonitrile" and "analine" ? What is the reference(s) for this process?

There's a lot out on the topic of nickel hydroxide electrodes. What method will work depends on the application, thus the need for references re the process. Note that high surface is typically but not always desirable, using simple sheet metal will give poor performance. One general method is to soak porous material in a solution of a nickel salt, often with small amounts of other elements for performance improvement, then heat in a reducing atmosphere to decompose the salt and convert it to porous nickel as well as to burn out the porous supporting material if it's organic. The porous nickel is then treated in one of several ways to develop the hydroxide layer, using it as a filter for a suspension of precipitated nickel hydroxide, electroplating a thin layer of powdery nickel then oxidising that in solution, and so on.

beastmaster - 11-11-2010 at 23:32

Spelling isn't one of my strong points sorry. My interest in a nickel hydroxide cathode was for possibly oxidizing Aniline to Acetonitrile. My reference though not specifically claiming to work for this is:

Attachment: s-1982-29721.pdf electro.pdf (105kB)
This file has been downloaded 506 times

It seems simple enough except for the nickel hydroxide cathode I have read several patients but they seem outside my skill range or they have the need of furnaces and what not.
I am mostly looking for an easy first project using electricity and easily obtainable reactants. Thought this was it. I guess I'll keep looking. Thank you.

not_important - 12-11-2010 at 12:33

"Oxidation of Primary Amines..."

Aniline is an aromatc amine, the nitrogen is attached to the benzene ring.

Acetonitrile is the nitrile of acetic acid, CH3CN. The oxidation in question, as show in the PDF, is the oxidation of the alpha methylene and the amino group R-CH2-NH2 => R-CN. Aniline is C6H5NH2, there is no alpha methylene to be oxidise although you might oxidise the amino group and the ring.

The surface area of a flat sheet electrode is small, most useful setup use electrodes with much high area. The referenced prep used a mesh electrode, without a real furnace to do a proper job would be to start with a sheet of nickle mesh, or lacking that a copper one (from hardware store) that you then heavily plate with nickle. Then precipitate nickle hydoxide, filter to get a thick much, coat that over the wire mesh. Heat with a flame, or in an old oven, to dry and partially decompose to nickle oxide. Repeat. This will be a rather fragile electrode, prone to falling apart, but the best you can do without higher temperatures. If you could heat it with a flame in the reducing zone, or in a ceramics kiln in reduction, hot enough to sinter the nickle formed, then electrolytic formation of a hydroide layer on that might work.

smuv - 14-11-2010 at 15:07

he means alanine

not_important - 14-11-2010 at 21:17

Ich weiß, ich bin versucht, nach Hause zu fahren, wie wichtig es Dinge richtig tun, wenn Wissenschaft.