Jstuyfzand
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Alternative way to make Mno2 anodes?
I was researching about anodes and such, and I came across this on wikipedia:
The manganese dioxide is dissolved in sulfuric acid (sometimes mixed with manganese sulfate) and subjected to a current between two electrodes. The
MnO2 dissolves, enters solution as the sulfate, and is deposited on the anode.
This seems like a really easy method to depoisit MnO2 on an electrode, especially if you can use MnO2 from batteries.
This post could be stupid or some breakthrough, I apoligize in advance for the first.
Kind regards
Jstuyfzand
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Xenoid
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It's a long time since I made any MnO2 electrodes! 
I recall trying to plate MnO2 onto graphite and Ti from an MnSO4 solution at 90oC. I don't think it adhered well!
You will need to plate onto an inert substrate such as Ti. To do this you require a thermally applied intermediate coat of something like Sb doped
SnO2.
There are many patents covering this subject, but in particularly you should look at US Patent No. 4,265,728 from 1981.
Examples 25 onward use electro-coating of MnO2 from both MnSO4 and Mn(NO3)2 solutions. Remember you still need to thermally treat (heat to about
400oC.) the coated electrode to convert the MnO2 to the beta structural form, which is the most electrically conducting and catalytically
active form of MnO2.
I found it was much simpler to just use the thermal decomposition of Mn(NO3)2 coating procedure and never bothered with electro-coating after the
initial failed attempts.
The MnO2 anode is suitable for making both chlorate and perchlorate.
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Jstuyfzand
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Quote: Originally posted by Xenoid  | It's a long time since I made any MnO2 electrodes!
I recall trying to plate MnO2 onto graphite and Ti from an MnSO4 solution at 90oC. I don't think it adhered well!
You will need to plate onto an inert substrate such as Ti. To do this you require a thermally applied intermediate coat of something like Sb doped
SnO2.
There are many patents covering this subject, but in particularly you should look at US Patent No. 4,265,728 from 1981.
Examples 25 onward use electro-coating of MnO2 from both MnSO4 and Mn(NO3)2 solutions. Remember you still need to thermally treat (heat to about
400oC.) the coated electrode to convert the MnO2 to the beta structural form, which is the most electrically conducting and catalytically
active form of MnO2.
I found it was much simpler to just use the thermal decomposition of Mn(NO3)2 coating procedure and never bothered with electro-coating after the
initial failed attempts.
The MnO2 anode is suitable for making both chlorate and perchlorate. |
I looked into the MnNO3 method, nurdrage did it, the only problem is that it is hard and expensive to get nitrc acid in the netherlands, and it would
require pure MnO2, so no batteries.
I am a very MacGyver style of chemist, I try to get my chemicals from everywhere except buying, since that often requires permits, for example,
fertilizer with a decent nitrate percentage is banned since the Breivik attack.
I will keep on looking, but I need a relatively simple procedure (Time consuming is no problem) because I am still in high school and all of my
knowledge is from Sciencemadness, and I wouldnt consider myself experienced enough to perform relatively dangerous/complicated synthesises.
PS: I can get Sulfuric acid from drain cleaner, and was thinking about making nitric acid with a birkeland eyde reactor.
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alive&kickin
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Jstuyfzand, I've been plating a lot of metals recently (see plating tin). I've never tried to plate MnO2 onto anything, but I'll give it a try and
let you know if I have any success. You want a U2U or post in this thread?
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Jstuyfzand
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| Quote: Originally posted by alive&kickin | | Jstuyfzand, I've been plating a lot of metals recently (see plating tin). I've never tried to plate MnO2 onto anything, but I'll give it a try and
let you know if I have any success. You want a U2U or post in this thread? |
Post it in this thread, so that others can also see this.
Thanks alot! Could you also describe the exact process?
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alive&kickin
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I'll be sure to post here with full description if I have any luck, quick note if failure. Someone else may have a better go at it than me, if so,
I'd like to hear it too. Attempt and results to follow soon.
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100PercentChemistry
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Hmm. Didn't NR make a video on that?
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Jstuyfzand
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He did!
But I think he deleted it, I cant find it anywhere!
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alive&kickin
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Jstuyfzand, like Xenoid, I've tried it on carbon rods. Plated but flaked right off, didn't really stick. Haven't had time to try anything else.
Anyone with any ideas as to what might work? Would be real interesting to find something simple and easy. Also, I'm not sure how pure my MnO2 is.
Haven't given up yet, still going to try when I get the time.
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hyfalcon
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Has anyone tried flashing a carbon rod with a bonding layer of some other metal first? Possibly tin? Might get better adhesion with a careful bake
in between.
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yobbo II
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Link
http://oxidizing.typhoonguitars.com/chlorate/mno2.html
Descriptions above
Yob
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