Various Electrolytes and Electrode Interactions [Chemistry Data]

[Dantes]

I am starting my testing of various metals [and graphite] (electrodes)  &  electrolytes.


I failed Chemistry, so I need some help determining solution by-products.


We know that using Stainless [Chromium] electrodes produce nasty chemical by-products.


We also know the dangers of NaOH and KOH.


Yes, they are being used a lot and are very productive. They can also be very safe if they are handled carefully
and treated with respect.


I do not want to really go down the "there is no danger, etc." road. I just want to establish facts and "it might" scenarios.


So, if you can post your Electrolyte - Electrode combination, that would be great.

Also, please include your Electrolyte Solution By-Products.


We need to establish what works. When we find what works, then we need to assess the Pro's and Con's.


I will be more than happy to create a nice, clean, list. I just need the data. This is for my own experiments and for
others that are just beginning their journey.


Please do not post anecdotal evidence. If you have a youtube video, or website, then back up your claims.


I don't want anyone to replicate a combination that may be dangerous or hazardous to their health.


No pissing contest either. Let's establish some data, then we can discuss the validity, etc.


So, please help me, the Chemistry novice, establish a great list !


Do a simple format that I can understand, ie: Stainless 316L and KOH = XXXXX by-product.

Let this be in your opening sentence, then you can following with your reasoning/explanation.

I'll grab the data and post it in one area here.

Thanks !

[Dantes]

This post reserved for accumulated data.

[TinselKoala]

304 SS + Distilled water + NaOH = gas + brown scum.

I have a small cell setup that I have just started experimenting with. The electrodes are 304 stainless, and I have tried water from my dehumidifier, commercial distilled water, tap water. For electrolyte I have tried NaOH, baking soda, vinegar, and none.
Right now I am sticking with Commercial Distilled Water and NaOH (2 pellets per 400 ml water).
I would like to use 316L but it is too expensive in tubular form--my local supplier will only sell 20 foot uncut lengths.
Initially I got the brown scum with all electrolytes (except "none" lol) . NaOH produced the most gas, I think. Baking soda was nearly as good. Vinegar isn't so good, but I used really old Heinz Malt Vinegar for fishnchips. I would bet glacial acetic acid would work better.
I will be trying sulfuric acid later.
I haven't seen any sign of a white powdery deposit forming on the electrodes.

Now that the cell has settled down there isn't much new brown scum forming.
I made a few videos, some good some not.
Note: I call these "DC" but they are really pulsed DC. Next I intend to  show straight filtered true DC, and some various other oscillatory waveforms.
The vids aren't on YouTube, you have to download them. I would appreciate it if they did NOT show up on YouTube. If I wanted them there I would have put them there.

http://www.mediafire.com/?xgxnmddzzmz
http://www.mediafire.com/?fnnuuwud0bc
http://www.mediafire.com/?2ywmchlrjmj

[Dantes]

Excellent TinselKoala !


Exactly the format and information I am looking to compile on this site.


One question though. What about the amount of Hexavalent Chromium ?


This is what is created when the Chromium leaches out of the SS due to the
process.

[TinselKoala]

Don't drink the water?


Actually I was unaware of that. I will check into the hazards. Thank you for bringing it to my attention. I do get a bit casual about exposures to hazards sometimes, and I shouldn't.
So it is probably a good idea to treat the brown scum as toxic waste...
Actually the scum is more properly a flocculent. It settles out nicely over night and the water can be decanted, the brown stuff removed, and the water replaced. I understand that after a while the brown scum is no longer generated, but I am not quite at that point yet with this cell.
Is the hexavalent chrome in the brown, or is it dissolved in the water?