Pt/Ir alloy as PerChlorate electrode

[Givat]

Hi all,

I'm thinking about buying small Pt\Ir wire to use as electrode in a PerChlorate cell.

This alloy is VERY(!) expensive.

I tried looking for any writing about using it or using pure Pt electrode in a perchlorate cell to see how much it corrodes, but couldn't found anywhere how much approximately it corrodes.

I don't want to buy a 0.25m"m thick wire and found it will disapear after 2 runs in a cell...

 

So I'm hope some one maybe got any writing or experience using Pt\Ir or pure Pt as perchlorate elctrode and can share it with me before I'll throw money for nothing.

 

thanks.

[asilentbob]

If you have IRC get on Slashnet and join #totsebb lordnitrox there has built and is running a cell with a Pt on some metal anode and a titanium cathode.

 

I would think that buying a reasonably sized anode, like 1/4"OD that is just Pt electroplated onto another material would be better, however where you could find that... i dont' know. Maybe you could get a place that electroplates Pt on things and get them to do it on a metal rod or wire mesh grid.

[markx]

According to russian literature:

 

"When using Pt anodes in a perchlorate cell under optimized conditions (current density, pH and electrolyte composition) the losses of Pt due to corrosion lie in the range of 7-10g per 1 ton of produced perchlorate. When temperature of electrolyte is raised over 40C and the concentration of chlorate ions is low the losses of Pt can raise sharply. Trying to convert the last 7% of the remaining chlorate ions in the electrolyte can lead to 400% raise in Pt losses (28-40g per 1 ton of produced perchlorate)."

 

IMO it's way more economical and straightforward to use PbO2 anodes for perchlorate production. They can be prepared for a fraction of the cost of a comparable Pt anode and last for a long time. Besides, you would not get any reasonable productivity with a small piece of wire anyhow. You have to up the amps quite a bit to get higher output rates but a small anode will quickly overpolarize and reach the potential of oxygen formation. In that case you quickly dissolve your precious alloy and mostly produce only O2 at the anode.

 

If you are interested I can look up the exact procedure for electroplating PbO2 on different substrates. There were several electrolyte compositions and methods for plating PbO2 layers.

[Caramanos2000]

I have used Tungsten electrode from welding shops. They dont erode at all. I ran them for 1 week at 6amps and they didnt even discolor.

[Umphrey]

I have used Tungsten electrode from welding shops. They dont erode at all. I ran them for 1 week at 6amps and they didnt even discolor.

Interesting. Did you use it as an anode or a cathode? At what voltage was it ran at? Did you use this in production of chlorates or perchlorates?

[Caramanos2000]

Anode. I ran it at 12v and at 6v. I tried to make chlorates but all I got was a fine white powder thats not flamable at all, might try again, but I dunno.

[Umphrey]

I tried to make chlorates but all I got was a fine white powder thats not flamable at all, might try again, but I dunno.

What do you mean "not flamable at all" An oxidizer by itself will never burn. Did you try to use it in a composition?

[kwinchee]

/CPR

 

I found a source for cheap Pt but it is Pt coated Ni would it be worth trying or would it just corrode striate away.

 

also form markx

what type of anode and cathode are we talking like a smallish thing or like a proper commercial cell as it seems hard to believe only a loss of 7% of like a 20g anode

[Caramanos2000]

Yes of course, still nothing.