Make Manganese Dioxide Electrodes (for chlorate or HHO cells)

How to make Manganese Dioxide Electrodes that can be used for chlorate cells or HHO cells and a few other electrochemical processes requiring inert anodes in oxidizing solutions.

Make the electrode is fairly simple. First a titanium strip is sanded to give a clean surface and then etched with hydrochloric acid to activate it. Cobalt nitrate solution is applied in a thin layer and then heated to 300 Celsius to decompose (pyrolyze) the cobalt nitrate into cobalt oxide. the loosely adhering cobalt oxide is washed off and then new layers of cobalt oxide are applied. Usually between 3 to 10 layers.

Then manganese nitrate is applied and the process repeated to make manganese dioxide. Another 10 to 50 layers may be applied.

Optionally, a further layer of manganese nitrate by electrolysis may be applied by using the electrode as an anode in a solution of 90 grams manganese sulfate, 500mL water and 12mL concentrated sulfuric acid. Copper or titanium is used as the cathode and a current density of about 10ma per square centimeter is used. A short run time of a few minutes or so puts a thin layer of manganese dioxide on the surface that seems to reduce permanganate production, but does not eliminate it.

In the future i'll be working on a lead dioxide electrode.

[NurdRage]

@coldsn In theory anything could work. but titanium is good because even if you missed a spot, get a scratch, or if there is some random flaking due to flexing or thermal expansion/contraction, the titanium won't corrode when it comes in contact with solution, it just passivates. A more reactive metal like copper or steel would start corroding, the corrosion then spreads underneath the layers and eventually the whole thing is destroyed.

Tantalum and niobium work too, but titanium is easy to get

[tjpld]

Haven't heard of anyone making a good PbO2 Anodes but still it is seen as the Holy Grail of Anodes for Perchlorate Cells since you can oxidize from KCL directly to KClO4.

[NurdRage]

@mV33rs Stainless steel (as it's called) only means stainless or "rust-free" under regular environmental conditions, rain, air, snow, salt, etc.

But under the extremely harsh conditions of an eletrolytic cell (especially chlorate) it's destroyed rather quickly.

Very few metals like platinum and titanium can take those kinds of conditions.

[ThePeterDislikeShow]

Can you get rid of the oxides on the titanium by running it as a cathode?

[NurdRage]

@Gmc42082 I intend to eventually make MMO electrodes too.

but yeah, this is not better than a commercial product. I just wanted to show a homemade way of creating a semi-viable electrode.

[MisterTHX]

you mentioned applying manganese dioxide electrolytically to a copper electrode. Is the initial cobalt layer required with copper?

[colin]

Hey Nurd, did you ever experiment with the lead dioxide electrode concept? I'm currently working on one myself and would look forward to you possibly covering the subject in a future video.

[NurdRage]

@TheMnO2 Very interesting! i'm intrigued by your use of vanadium. Thanks for sharing. you really should make a video on your process!

[NOBOX]

i wonder if rapping the anode in string would give the dope extra integrady ?
i am going to try rapping a carbon anode in cloth very tightly but using a thin layer,
i think that wen sum materials absorb the elite they are "exploded " from the inside by the evolusion of gases?

[runkert]

i love these videos, i love the feeling of actually understanding most of it. the best part is not understanding all of it. thanks for another brilliant vid guys!

[NurdRage]

@mV33rs Titanium is best due to it's chemical inertness and mechanical strength. Other materials would dissolve if even a tiny bit of manganese dioxide was scratched off.

[NurdRage]

@blakewade01 There are better materials than cobalt oxide, but cobalt is the easiest one to get. Sold at pottery supply stores by the pound.

[NurdRage]

@AngryBF2Nerd no, it just has more to flake when you have 20 layers. the rate of flaking is still the same.

[NurdRage]

@sciencoking If you can find a way to electroplate cobalt oxide (using home-lab setup) let me know. :)

[techhaxrz]

THANK YOU, FINALLY A VIDEO THAT EXPLAINS WHAT I WANTED!~!!!

[NurdRage]

@j822bosh its a good idea, i haven't tried it yet, but certainly worth looking into.

[Ar]

Wow yours is the 1st video ive seen where all the captions represent what you are saying.

[NurdRage]

@The0Burger0King that substance itself would probably be destroyed under oxidizing conditions.

Lead dioxide would work, but then i would use a pure lead dioxide electrode instead :)

[NurdRage]

@coldsn its a great idea and worth testing. I don't have the equipment to perform such tasks but if you could let me know your results. Eventually in the future i might get/build something that can do those things. its certainly an interesting idea.

[NurdRage]

@capnquack the oxides are far too brittle to be hammered. It might work with a malleable metal like copper, but hammering oxides is like hammering rock, it just breaks it.