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Author: Subject: Organic oxidizers which can be electrochemically recycled
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[*] posted on 12-2-2019 at 22:38
Organic oxidizers which can be electrochemically recycled


I am working on a project (for a company which I signed an NDS with so I cant name anything too specific here) which I am currently using hydrogen peroxide as a oxidizing agent. I was thinking that it might be interesting to try some other oxidizers which could potentially be electrochemically regenerated outside of the reaction cell so that multiple runs can be preformed without diluting my solution with water generated from the decomposition of the peroxide. I am oxidizing the surfaces of solid materials which are non-conductive so I cant hook the material directly to a power supply to oxidize.

Are there any molecules which can act as moderate to strong oxidizers which can be regenerated electrochemically?

As a side note, I am currently experimenting with O2 gas... appears that the reaction is kinetically unfavorable with O2 at STP but I am going to keep trying.

Thanks in advance for any help!
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[*] posted on 13-2-2019 at 00:15


Perhaps you could try DDQ? See for example this paper: https://onlinelibrary.wiley.com/doi/full/10.1002/adsc.201601...



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[*] posted on 13-2-2019 at 20:59


With your O2 gas - have you considered ionising it at low pressure? Either RF or dielectric barrier discharge will generate a plasma with reactive oxygen species.
I built such a system at one of my previous jobs in order to modify the surface of some plastic parts to improve glue adhesion. Which it did extremely well (5x increase in bond strength).

Search the web for "Plasma cleaning" and you should find examples.

Here's the one I built: https://4hv.org/e107_plugins/forum/forum_viewtopic.php?p=1&a...




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[*] posted on 14-2-2019 at 14:17


Tempo might work for that, not sure. Also some dyes (Rose Bengal maybe?) react with oxygen and UV to make excited state oxygen or such which which can oxidize some compounds specially. Not my area, but I would think that there are some ways to do that.
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[*] posted on 14-2-2019 at 19:56


Thank you all for your responses, I know I really didn't give much to work with here. We are in the initial phases of this project and I am just trying to do some scoping to see of we can get a response or not. Currently I am using hypochlorite generated in situ (hense the peroxide ;) ) as an oxidant- this works really well except, water degrades our reaction products... In addition, the use of chlorine gas is off the table apparently.

Thus I need to either regenerate hypochlorite, or find an oxidizer which can replace it. I know that a few of the oxidizers mentioned and be regenerated with hypochlorite --> chlorine ion (ex tempo) thus I need to find something which is a stronger oxidizer than hypochlorite.

I am looking into DDQ to see what its potential is- thanks metacelsus.

Again thank you all for your help on this, I am a bit out of my element here.





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[*] posted on 15-2-2019 at 00:29


DDQ is only stable in water under acidic conditions, so I don't think it would be compatible with hypochlorite. Of course, it sounds like you might be interested in getting rid of water entirely, in which case it might work. The standard reduction potential of DDQ is about 1 V depending on solvent. Without more information, I can't really give better advice.

[Edited on 2019-2-15 by Metacelsus]




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[*] posted on 15-2-2019 at 08:35


I don't know of any oxidizer cheaper than hypochlorite, you can buy it by the tanker car load for little. And it is made industrially by electrochemistry, so while you could try to build a system for it, there are already people making it that way, in bulk. So unless you are building a major plant, I can't imagine a cheaper oxidant source than bleach.
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[*] posted on 15-2-2019 at 15:41


True, bleach is nice and cheep, however for this application (think sensors) that it would be impractical to constantly add chemical.

For those who stumble across this thread in the future, I did find an article on regenerative electrochemical synthesis. I wouldn't have found this if it wasn't for the suggestions from you all so thank you a ton for that.

I think I will try for the hypochlorite directly first, and then move on to some more exotic reagents such as DDQ.
I can operate with a small amout of water present, but a dry reaction would solve a TON of problems.

Attachment: organic synthesis with electrochemically regenerative agents.pdf (3.8MB)
This file has been downloaded 40 times




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[*] posted on 15-2-2019 at 17:24


intense u.v. could maybe work directly, or indirectly to create ozone ?
or some other ozone generator ?




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