Sciencemadness Discussion Board

Acquiring MMO anodes

Markovfff - 7-11-2017 at 09:28

Greetings,
I want to buy some electrodes from store.theamateurchemist.com.
My question is does this shop still works, and did someone already ordered from it ? Or if anyone knows other stores with MMO's I would like to know them too :)


[Edited on 7-11-2017 by Markovfff]

Melgar - 7-11-2017 at 15:37

I have extras, 1"x10". How many do you need? I could spare one or two. There's an eBay seller... his name has the word "laser" in it, who has a bunch of them, but doesn't always have an auction listed because of the low demand. Search around in this forum for his username there, and send him a message, and he'll probably put the auction up for you.

Funkerman23 - 16-11-2017 at 20:07

Would the exposed titanium metal on the anode passivate in a Chlorate cell or would it kill chlorate synthesis? I know he had some 1 in wide strips but I missed out.

Melgar - 16-11-2017 at 20:53

Quote: Originally posted by Funkerman23  
Would the exposed titanium metal on the anode passivate in a Chlorate cell or would it kill chlorate synthesis? I know he had some 1 in wide strips but I missed out.

Their main use is as anodes in chlorine-containing environments. Often, for electrically protecting metal that's exposed to saltwater.

[Edited on 11/17/17 by Melgar]

woelen - 17-11-2017 at 00:08

The titanium becomes passivated and is not corroded in a chlorate cell.
Remarkably, in a bromate cell the exposed titanium is corroded.

Markovfff - 19-11-2017 at 06:16

I appreciate Your help. One more question, I need a titanium mesh cathode too, and i found only this on ebay that meets required sizes :

https://www.ebay.pl/itm/Titanium-Mesh-Perforated-Plate-7-87-... . I can't contact this seller. Anyone know what which grade is this mesh ?

I thought the same about exposed edges on laserred's MMO's but then I recalled that titanium passivates when used as anode.

[Edited on 19-11-2017 by Markovfff]

Markovfff - 20-11-2017 at 06:45

I ordered an anode from Laserred's store, thanks for showing me him. I contacted this supplier from China and he told me that this mesh is TA1(grade 2).

markx - 21-11-2017 at 02:25

Quote: Originally posted by Markovfff  
I appreciate Your help. One more question, I need a titanium mesh cathode too, and i found only this on ebay that meets required sizes :

https://www.ebay.pl/itm/Titanium-Mesh-Perforated-Plate-7-87-... . I can't contact this seller. Anyone know what which grade is this mesh ?

I thought the same about exposed edges on laserred's MMO's but then I recalled that titanium passivates when used as anode.

[Edited on 19-11-2017 by Markovfff]


You do not specifically need to use titanium as the cathode material in a chlorate cell, although it is most profoundly inert to the corrosive effects of the electrolyte. But most "garden variety" stainless steels will also work fine in this application. Even regular mild steel can be used in principle, but one has to watch out for not immersing the cathode in the electrolyte without the power applied. Lack of cathodic potential will cause fast dissolution of the cathode material into the electrolyte and contamination of the latter. The same also applies to most stainless steels...they will corrode fast if left immersed in the electrolyte with the power supply turned off. With titanium this is not going to happen, but another interesting effect will appear: titanium readily absorbs hydrogen under cell operating conditions and notably deforms due to that. Usually the titanium cathode plates tend to bend away from the anode in a uniform arc as the hydrogen migrates into the metal from the side of highest current density and expands the cristal lattice in the process. The effect is reversible, as after some time of not operating the setup, the hydrogen will diffuse out of titanium and the cathodes regain their former geometry.

Markovfff - 21-11-2017 at 09:04

I knew that with cathodic protection even copper would do the job (well, almost). With titanium I'll get a bonus to efficiency for free, its not much important in amateur cells but thats always something and I wont need to worry about corrosion as you said before. I didn't knew that about titanium, so thanks, you probably saved me from being frightenned that I f***** up something again :D.


[Edited on 21-11-2017 by Markovfff]