Sciencemadness Discussion Board

perchlorate cell questions

mysteriusbhoice - 27-11-2020 at 05:29

so I ran my perchlorate cell for 1 day at 14 amps 180ma/cm^2 with my MMO PbO2 plate anode and Ti mesh cathode and did get a positive test for perchlorate.
Now online conversion tells me I should have a considerable amount of perchlorate after 1 day but that doesnt seem like the case.
The cell isnt saturated NaClO3 could that be the reason? I used sulfate since I could not find persulfate.
I did do a precipitation test using KClO3 saturated solution and some crystals did appear after additing but too much compared to me adding some sodium perchlorate solution from cooking runs.
Vid is below:
https://youtu.be/QMNkZXXr3vc

I really wonder if its possibly due to not being a completely saturated solution.

mysteriusbhoice - 28-11-2020 at 03:56

finally producing product video of cleanup soon!!

markx - 1-12-2020 at 03:46

I've rather repeatedly observed a considerable delay in the formation of sodium perchlorate during electrosynthesis with a platinized anode. Usually it takes in excess of 24h before the process starts to produce perchlorate efficiently and the percipitation tests with KCl seem to confirm it. Methylene blue may detect minuscule amounts of perchlorate after a short while, but it seems that the main formation is somewhat delayed. So I would not worry about the lack of product after just 24h. Let it tick for a few days and then assess the progress.

mysteriusbhoice - 1-12-2020 at 20:42

Anyways it turns out my homemade PbO2 electrode from lead chlorate works really well and I'm currently running it again for a second run

mysteriusbhoice - 3-12-2020 at 00:20

when does ozone evolution take place in the cell and does that affect PbO2 in terms of wear rate.
2nd run right now is using crude chlorate and tiny amounts of PbO2 were in suspension after some time due to chloride unlike previously using purified chlorate 99% as feed.
how does ozone evolution affect PbO2 in terms of wear rate if any.
Overall checked my electrodes and it still have an nice black to gray iridescent finish to them and not powdered brown when dried.
I mean I will be able to find out soon enough but I want to know in advance if its significantly detrimental to go to the ozone evolution phase.

1st run ended early
https://youtu.be/JZWofKi_K8w
due to having to shift house

[Edited on 3-12-2020 by mysteriusbhoice]

mysteriusbhoice - 7-12-2020 at 22:26

Quote: Originally posted by markx  
I've rather repeatedly observed a considerable delay in the formation of sodium perchlorate during electrosynthesis with a platinized anode. Usually it takes in excess of 24h before the process starts to produce perchlorate efficiently and the percipitation tests with KCl seem to confirm it. Methylene blue may detect minuscule amounts of perchlorate after a short while, but it seems that the main formation is somewhat delayed. So I would not worry about the lack of product after just 24h. Let it tick for a few days and then assess the progress.


DO you think forward feeding NaClO4 or KClO4 into the cell as an additive will help bump up perchlorate production due to the initial concentration of perchlorate being present??

mysteriusbhoice - 12-12-2020 at 20:01

well ive done 2 runs with PbO2 electrodes and because I have no persulfate my efficiency seems to be around 50% even at 207ma/cm^2 but prolly because I assume the current is only going to one face of my anode since its a flat plate type.
It could just be that 24 hour delay but ive forward fed NaClO4 onto my second run and it removed the 24 hour delay but still only half my stuff was converted.
Good news is that I have more than 1kg of NaClO4 and just need to purify with acetone as for the electrolysis it means I just have to run it longer I guess.

[Edited on 13-12-2020 by mysteriusbhoice]