Sciencemadness Discussion Board - Thoughts On Anodes

Thoughts On Anodes

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dann2 - 6-8-2011 at 05:41

Perhaps it's time to invest or make a high temp. oven/furnace.
The homemade oven I have would only go up to 800C (or so I suppose). It's a very crude affair but good for 500C or so for making Tin Oxide, MnO2 etc on Ti Anodes.
It does not even have temp. controll just a variac on input element.

Dann2

jpsmith123 - 6-8-2011 at 10:03

Well if the stuff works you could probably get your money back (and then some) selling perchlorate anodes on ebay.

BTW here's an abstract of a paper that claims a method to make bismuth tin pyrochlore at 873 degrees K (600 C).

http://www.sciencedirect.com/science/article/pii/S0167577X99...

#######################

I was looking into bismuth tin pyrochlore and I happened to come across the following (which I also requested in the "wanted references" section):

Distinctive Tin Dioxide Anode Fabricated by Pulse Electrodeposition: High Oxygen Evolution Potential and Efficient Electrochemical Degradation of Fluorobenzene

Tao Wu, Guohua Zhao*, Yanzhu Lei, and Peiqiang Li
Department of Chemistry, Tongji University, Shanghai 200092, China

J. Phys. Chem. C, 2011, 115 (10), pp 3888–3898
DOI: 10.1021/jp110149v
Publication Date (Web): February 21, 2011

Abstract
A distinctive Sb-doped SnO2 anode with a high oxygen evolution potential, 2.4 V vs the saturated calomel electrode, and a strong electrochemical oxidation ability was prepared on TiO2 nanotubes through the pulse electrodeposition method. Compared with the traditional Sb-doped SnO2 electrode prepared by the sol−gel method, the proposed SnO2 electrode has a higher crystallinity, a higher order degree of the atomic lattice, and a lower concentration of oxygen vacancies. The scanning electron microscopy image confirms that the surface of the electrode presents a three-dimensional structure consisting of Sb-doped SnO2 nanoparticles with a certain microspherical structure, which increases the specific area greatly and provides more active sites. The reaction activation energy also decreases from 11.67 kJ mol−1 for the traditional SnO2 electrode to 5.73 kJ mol−1. This SnO2 electrode is demonstrated to have a superior electrochemical oxidation ability for refractory fluorobenzene, which is extremely stable and cannot even be degraded effectively on a boron-doped diamond electrode with a strong oxidation capacity. The results also indicate that the distinctive SnO2 electrode has a higher apparent rate constant, total organic carbon removal, and mineralization current efficiency, which are 12, 2.6, and 3.3 times those of the traditional SnO2 electrode, respectively. The evolution of intermediates and the degradation mechanism of fluorobenzene were further discussed. This study provides a distinctive SnO2 anode for the effective electrochemical oxidation of refractory toxic organic pollutants.

[Edited on 6-8-2011 by jpsmith123]

jpsmith123 - 7-8-2011 at 10:33

Well Solo came through as always with the paper I asked for, but unfortunately it's partly written in "Chinglish"...just like the documentation you would expect to get with any new piece of Chinese manufactured computer hardware.

Apparently the authors attribute the excellent performance of their anode in part due to the TiO2 nanotubes and in part due to their method of electrodeposition of the Sb doped SnO2.

This paper is interesting to me in part because, unless I missed something in the text, the anode is apparently ready to use just as it comes out of the plating tank, whereas other papers I've seen on electrodeposited SnO2 describe a high temperature annealing step which enhances the crystal structure and makes the material more durable.

Anyway, what I was specifically interested in, in this paper, was the details of how they went about directly electrodepositing Sb doped SnO2...as it might be a generally useful method workable with other substrates and other dopants.

To that end I've read the relevant part of the text about three times, and I still don't fully understand their process. Unfortunately, not only is their method very imprecisely described (e.g., "a certain concentration of hydrochloric acid"; LOL!) but the text dosen't seem to match the pictorial description very well.

I've seen other papers where doped SnO2 was directly cathodically deposited, in a solution that used nitric acid as an oxidizer; and in another case where O2 was bubbled into the solution; and I've read where adding H2O2 will work also.

And I have another paper where Sn and Sb were sequentially electrodeposited in layers (by conventional cathodic electrodeposition) and after a few alternating layers were deposited, the electrode was calcined @ 550 degrees C for 3 hours in air to go from Sn to SnO2. (Also, in this paper, the electrodeposited SnO2 was compared to conventional dip-and-bake Sb doped SnO2 and it was found to be much better, similar to what's described in the instant paper).

In this case, my take is that the bipolar waveform is the key. The Sn and Sb are deposited when the substrate is pulsed negative, and subsequently oxidized when the substrate is pulsed positive. (IIRC Beer used AC in some of his patent examples apparently to do the same thing).

So here's my idea: instead of Sb, we want to try bismuth (but who knows maybe electrodeposited SnO2 + Sb will work better for perchlorate than the dip-and-bake variety), so how about substitute BiCl3 for the SbCl3?

(Attached is the other paper I was referring to).

Attachment: php9wSGCj (554kB)
This file has been downloaded 1859 times

##############################

Edit: Here's an example from one of Beer's patents...looks like basically the same thing to me, just substitute your favorite chloride salt...

Two titanium rods were degreased and pickled and subsequently placed in a galvanic bath having the following composition:

100 cc. ethanol
100 cc. water
1 g. ruthenium chloride
10 g titanium chloride

and subsequently connected to a source of alternating current of 13 volts and a current density of 15 amp/m^2, temperature 20-30 degrees C., for a period of about 20 minutes.

After about 20 minutes both rods were coated with a mixture of titanium oxide and ruthenium oxide, the adhesion of which was still further improved by heating at 400 degrees C for 5 minutes.

The anode thus made is excellently suitable for use in various electrolyses at low current densities.

[Edited on 7-8-2011 by jpsmith123]

dann2 - 7-8-2011 at 18:12

I read the paper on the TiO2 nano tubes and it sounds like the business. They state it has very high OEP in a solution of Fluoro stuff they are 'incinerating'. This does not necessarly mean it will have a high OEP in a solution of Chlorate (a Perk. cell).

I don't know what they mean when they say:
'TiO2-NTs were vertically placed into a buffer bottle under
vacuum conditions.'

What is in the 'buffer bottle'?, .........
'The electrolyte containing 0.02 M
SnCl2 3H2O, 0.02 M SbCl3, and a certain concentration of
hydrochloric acid for 5 min' , ......perhaps.
Or is the 'buffer bottle' one of two (joined using a tap) compartments. No1 (buffer bottle) contains anode + vacuum and No2 has electrolyte. The air being sucked out of No. 1 and when all air is removed the electrolyte is then let flow into the 'buffer bottle' , all remaining under vacuum untill anode is submerged. Then air pressure caused electrolyte to flow into nanotubes.
Since they say 'a certain amount of HCl acid' perhaps its not a critical amount of acid, but just enough to keep SnCl2 from turning to Oxide (ie. hydrolysing)
The is an email address at the bottom. Perhaps author will answer questions.

I tried to make a Bi doped Sn Oxide Anode by simple substituting Bi Trichloride (homemade) for the Sb Chloride and could not get it to work. Just ended up with passivated Ti. I am currently getting around to trying it again using anhydrous SnCl4 + Anhydrous BiCl3. I used SnCl4:5H20 + BiCl3:?H20 last time. (homemade BiCl3)
Substitution may or may not work. My work could perhaps be described as amateurish

Dann2

jpsmith123 - 7-8-2011 at 21:04

Quote: Originally posted by dann2

I read the paper on the TiO2 nano tubes and it sounds like the business. They state it has very high OEP in a solution of Fluoro stuff they are 'incinerating'. This does not necessarly mean it will have a high OEP in a solution of Chlorate (a Perk. cell).

What's important, I think, is that the electrodeposited SnO2 worked better than the dip-and-bake SnO2. (And the other paper I attached to an earlier post also said the same thing).

Quote:

I don't know what they mean when they say:
'TiO2-NTs were vertically placed into a buffer bottle under
vacuum conditions.'

What is in the 'buffer bottle'?, .........
'The electrolyte containing 0.02 M
SnCl2 3H2O, 0.02 M SbCl3, and a certain concentration of
hydrochloric acid for 5 min' , ......perhaps.
Or is the 'buffer bottle' one of two (joined using a tap) compartments. No1 (buffer bottle) contains anode + vacuum and No2 has electrolyte. The air being sucked out of No. 1 and when all air is removed the electrolyte is then let flow into the 'buffer bottle' , all remaining under vacuum untill anode is submerged. Then air pressure caused electrolyte to flow into nanotubes.
Since they say 'a certain amount of HCl acid' perhaps its not a critical amount of acid, but just enough to keep SnCl2 from turning to Oxide (ie. hydrolysing)
The is an email address at the bottom. Perhaps author will answer questions.

The paper is really poorly writen.

Quote:

I tried to make a Bi doped Sn Oxide Anode by simple substituting Bi Trichloride (homemade) for the Sb Chloride and could not get it to work. Just ended up with passivated Ti. I am currently getting around to trying it again using anhydrous SnCl4 + Anhydrous BiCl3. I used SnCl4:5H20 + BiCl3:?H20 last time. (homemade BiCl3)
Substitution may or may not work. My work could perhaps be described as amateurish

Dann2

Did you make or buy your BiCl3?

I'd like to try the electrodeposition method, as described in Beer's patent, using SnCl2 and BiCl3. I'm trying to find a cheap source of BiCl3 but I'm not having much luck.

dann2 - 9-8-2011 at 07:40

Any experiments I have done up to now have been done using homemade Bismuth Trichloride (BiCl3:3H2O). I am not too sure how many H2O's. The non anhydrous stuff is easy to make using Bismuth metal + Aqua rega.
I have since purchased a small amount of BiCl3 which I presume is anhydrous. It just says BiCl3 on the bottle.

If you are going to go the electrodeposition route then the water should not be a problem.

Dann2

[Edited on 9-8-2011 by dann2]

the mentalist - 9-8-2011 at 08:54

Does anyone have a link to swedes blog that he mentions? I know that he posted a few links but none of them seem to work, or does he even have a blog anymore?

dann2 - 9-8-2011 at 13:54

Swedes blog can be had on APC forums:
You will neen to subscribe and go to a post of Swede and a link will be close to his name.
http://www.amateurpyro.com

@jpsmith
There is another paper here using Ti02 nano Tubes with Copper in the bottom of them (for a superior Anode). It may be a bit clearer. It's in relation to PbO2 though.
http://pubs.acs.org/doi/abs/10.1021/es902336d
Dann2

[Edited on 9-8-2011 by dann2]

watson.fawkes - 9-8-2011 at 15:34

Quote: Originally posted by dann2

Swedes blog can be had on APC forums

http://www.amateurpyro.com/forums/blog/swede/index.php

jpsmith123 - 9-8-2011 at 15:41

Upon doing some more reading, I think I'm going to go with the plating method described in patent #4252618 (attached), but I'm going to try it with AC.

This method uses potassium stannate, KOH, and bismuth citrate. It seems to have become an industry standard for electroplating Sn/Bi alloy.

I'm wondering, in any of your experiments, did you happen to try SnCl2 with BiCl3? The reason I ask is because I saw a patent for an electroless plating solution where SnCl2 is the reducing agent that plates out Bi.

Attachment: US4252618.pdf (102kB)
This file has been downloaded 822 times

dann2 - 9-8-2011 at 17:29

I have never tried SnCl2 with BiCl3, only ever used/tried SnCl4:5H2O

I could never get anything to work with SnCl2 (with Sb Chloride) in the simple paint and bake procedures.
Dann2

the mentalist - 10-8-2011 at 09:48

Does anyone know of a supplier that will sell mmo anodes to individuals? Cause it seems as if all suppliers require you to either be a company or buy mass amounts.

jpsmith123 - 11-8-2011 at 16:32

It's frustrating when you want to do a little experimenting and then you find you cannot get the necessary chemicals at a reasonable price.

I found a company that had both potassium stannate and bismuth citrate, at a good price, and then I went to check out - only to find that they had a $100 minumum order. Rats!

Does anyony know if Bi2O3 will dissolve in a citric acid solution?

Effect of Solvent on the Preparation and Characterization of DSA-Type Anodes

jpsmith123 - 12-8-2011 at 14:34

Dan, check out the attached paper.

Attachment: Effect_Of_Solvent_On_DSA_Anode_Performance.pdf (716kB)
This file has been downloaded 983 times

White Yeti - 17-8-2011 at 23:46

Bi2O3 won't work. It really looks like a good anode material, but it is not resistant to attack by acid. It will dissolve in hydrochloric acid to give a corresponding bismuth chloride.

jpsmith123 - 18-8-2011 at 06:42

Bi2O3 won't work for what?

White Yeti - 19-8-2011 at 10:46

It won't work for making anodes for perchlorate cells. You mentioned a patent earlier that stated bismuth oxide could be used to make anodes for perchlorate cells.

jpsmith123 - 19-8-2011 at 14:39

As far as I know, there are no patents mentioned anywhere in this thread (or anywhere else for that matter), that claim that Bi2O3, by itself, will suffice for a perchlorate anode. From what I see in the literature, it's always used with other oxides.

dexterrius - 22-8-2011 at 10:32

I made a chlorate cell but i dont need it any more so i am thinking about to sell it, it is capable of producing 1,5 kg of KClO3 per day, monopolar,
it consumes 15kWh electricity per kg of chlorate, massive carbon
anode(i made 30kg of chlorate with it, it coroded aproximately 5% of
its mass), it is a complete plant with power supply(1kW) ready to run,
the electrolyzer is a 120litre plastic drum with removable top, sealed
with silicone, anode is a 30kg carbon block(20x30x30 cm), the cathode
is made from stainless steel, input is 5,6V 160-180A at
50°C(stationary temperature of the drum at outside temperature 20°C),
aditional cooling fan to cool the drum during hot days, aditional
chlorate isolating equipment, power supply runs on 220V but the
secondary coil has aditional turnings so its easily switched to
operate on 110V however at lover currents(120-140A) what means lower
energy loss in wiring, contacts and electrolyte lowering the specific
energy consumption

i will send photodocumentation to serious candidates
location is Slovakia, transport can be arranged

Some bedtime reading...

jpsmith123 - 22-10-2011 at 19:42

I don't know how relevant this is, but it does seem to induce sleepiness.

stygian - 22-10-2011 at 20:04

Wow, the title itself made me say "wahaaat?"

dann2 - 7-11-2011 at 14:03

The Anode I have made (described above) seem to be holding up pretty well in perchlorate cells. There is little or no wear. They have been running now for about 40 days.
One of the Anodes is shown in picture. It was mostly used to scavange chlorate, ie. reduce the chlorate concentration of Perchlorate cells from about 20 grams per liter down to below one gram per liter. Chemical treatment of the liquor will be used to get rid of the last remaining remenents of Chlorate.

Dann2

Squall181 - 7-11-2011 at 17:22

Not sure if this has been discussed or not but, is there a way that lead nitrate can be decomposed unto a suitable substrate just like manganese nitrate to form a conductive oxide layer.

dann2 - 7-11-2011 at 18:36

No and no IMO.
Lead Monoxide will form AFSIK if you heat Lead Nitrate.
Dann2

gregkdc1 - 8-11-2011 at 08:12

All right Dann is that the Bi/Sn oxide anode or is it LD? If it is the Bi/Sn please tell us more. It would be very nice to see that it's working.

New Chlorate Cell

remigallard - 8-11-2011 at 19:54

I am finally starting construction of my first (per)chlorate cell. As seen in the picture i have to MMO anodes, there about 24.5cm by 5 cm. The basis for my cell will be the pvc pipe, which is 4 in thick. My first question is will pvc work for this? Im pretty sure that i remember sweed saying that it will work, but I'm not sure. Anyways, my idea that the stopper at the far right of the picture will be the bottom of the cell, i do have primer and cement to hold everything together. From there i can cut the main pvc pipe to the according size it needs to be. The end cap will be on the top, cemented onto the main pipe and from there the cap can be screwed on and off, i'm hoping this will allow me to have a chlorate anode/cathode set and a perchlorate anode/cathode set. Okay so now for a few questions. I have two mom sheets, they are obviously not connected together, is there any feasible way to connect them, like a electro conductive glue or a spot welder, not that i have one of those, I don't really think that either of those ideas will work so yeah. Next, will i need to trim down the main piece of pvc pipe so that the mmo anode just about reaches the bottom or can there be some room between the bottom of the cell and the bottom of the anode, and if so how much room? Oh and the cathode is a stainless steel sheet, its just not pictured. And my power supply is a batter charger that has two settings, 2amps with 12 volts and 4amps with 6volts. Also i will need to cut holes in the top cap to put the anode, cathode and venting tube, what type of material should i use to hold these in place? Is there some type of ceramic concrete or something that works best? Any suggestions and help will be greatly appreciated.

dann2 - 8-11-2011 at 20:12

Thanks for asking. The Anode is Lead Dioxide. I have just realized that I posted in the wrong thread. Mean to post the picture in 'More on LD Anodes'.
I think it all the Lead Nitrate I have eaten that may be the problem................

@Remiggalard
Taking one Anode you have 24.5 x 5 by two (sides) giving a total surface area of approx. 245cm^2. If you use the Anode at 100mA per square cm (lowish current density) that will mean your cell will demand 24 Amps.
The Anodes are far too big for the cell you are building. Half of one of them (or far less) would do.

Some reading here: www.oxidizing.110mb.com

remigallard - 9-11-2011 at 13:33

Thanks for your input dann2. If i were to cut on of the anode in half and have two anodes separated by a cathode in the middle, would that configuration work or would that still require the same amount of amps? Thats just a question of curiosity on how that works.

If i were to buy this, http://www.ebay.com/itm/5V-40A-DC-Universal-Regulated-Switch... its a 5volts 40 amp dc power supply, would there be any way to connect the two anode i have? or would i be better off buying a power supply that provides more so around 20 amps? Also if anyone has suggestions on what kind of glue i can use to seal the cathode, anode and vent tube to the top, I don't want the glue to corrode, or will it?

dann2 - 9-11-2011 at 15:22

Polyester resin is good for sealing Anodes and Cathodes.

Each piece of MMO that you have is capable of 'running' 50 amps (a current density of 200mA per square cm).
How big do you want the cell to be? ie. how much Chlorate do you want per day.

The 5 volt 40 amp supply will work OK. There is nothing wrong with the supply.

Don't use one cathode and two anodes, use one anode and two cathodes.

gregkdc1 - 23-12-2011 at 14:32

Just a few more "thoughts" on anodes. I have read this thread in its entirety as well as the PbO2 thread and Dann's site. One area I haven't seen to much discussion on is manganese dioxide anodes for perch production. I saw that Xenoid did some work in this area and had some limited success in particular when doping the MnO2 with Bi. There is a patent out there that discusses this and I think it was where he was getting his information.

Anyway that same patent discusses using ethyl silicate to deposit up to 20% of the oxide layer with SiO2 and claims to substantially increase the life of the anode. Now this raises a few questions for me.

First, do you have to control the Ph in a cell that has SiO2 in the oxide layer? I ask because isn't SiO2 reactive in strong alkali solution forming silicates?

Also if the SiO2 does get dissolved in a high ph solution does this open up the door to possibly using a silicon anode? I was under the impression that you can't use silicon because the SiO2 that is formed passivates the anode, but this should be converted into soluble Na2SiO3 in a high Ph solution.

Has anybody ever tried making an anode with SiO2 and Bi combined in the MnO2 layer?

Last if SiO2 proves to be impractical could you replace it with TiO2 using nitrate decomposition? Ti(NO3)4 may be easier to come by than the ethyl silicate; however I am having a hard time finding any information about Ti(NO3)4 because of all the idiots that don’t know the difference between nitrate and nitride.

Xenoid - 23-12-2011 at 15:15

Quote: Originally posted by gregkdc1

One area I haven't seen to much discussion on is manganese dioxide anodes for perch production. I saw that Xenoid did some work in this area and had some limited success in particular when doping the MnO2 with Bi. There is a patent out there that discusses this and I think it was where he was getting his information.

Hi gregkdc1, it's a long time since I did anything with anodes. But yes, I do recall producing perchlorate with MnO2 and I recall posting the information on the forum somewhere. I can't remember the details as to whether it was doped with anything, (just found some notes, they say it was pure MnO2) but I do recall it was thermally deposited over MMO (an old swimming pool chlorinator). Depositing on MMO is a good approach as it provides a very stable adhesive base. I think dann2 has tried this approach as well.

By the way, when trying to make perchlorate always use sodium chlorate as the starting material, and produce the KClO4 by double dissolution with KCl. It is way too inefficient using KClO3.

I did actually start a comparative study of solid Pt, plated Pt, and MnO2 coated MMO anodes of roughly the same size, however the logistics became too difficult, and I realized I could not find a simple quantitative analytical method for perchlorate. In addition I used KClO3 and this produced very poor results!

One of the problems with trying different perchlorate anodes and doping MnO2, as mentioned above, is comparing the results. I think I came to the conclusion that a perchlorate specific ion electrode was the way to go for analysis, but they are very expensive.

I now have a large solid Pt anode

which I made from an "old" Pt crucible. It makes perchlorate at an incredible rate, much faster and more efficiently than a Pt plated Ti anode.

Edit: Found the relevant posts here at the bottom of page 12 in the Technochemistry: Multilayer Metal Oxide / Titanium Anodes for Chlorate/Perchlorate thread.
"Some notes on MMO/MnO2 anodes from a while back!"
http://www.sciencemadness.org/talk/viewthread.php?tid=9783&a...

Looks like I did try doping with Bi and Co but I didn't fully evaluate their relative performance, mainly because I was messing around with KClO3 rather than NaClO3 most of the time, therefor the efficiency would have been poor for any type of perchlorate anode.

[Edited on 24-12-2011 by Xenoid]

gregkdc1 - 23-12-2011 at 19:13

My thoughts are this.
> It is known that MnO2 will make perchlorate but wear rates are high so it is never taken seriously, why not work on methods to increase the lifespan of the anode?

> This patent claims that doping up to 20% of the oxide layer with SiO2 will greatly increase the life span of the anode. I question how long SiO2 will last in a high Ph solution and I think TiO2 may be a better alternative if the oxide layer remains conductive and structurally sound . http://www.wikipatents.com/US-Patent-4072586/manganese-dioxi...

> Here is some of your previous work concerning MnO2 anodes with Bi dopant go down to the last experiment on the page. The Bi doped anode seems to be the anode with the best results for perchlorate? http://oxidizing.110mb.com/chlorate/xenoid_mn.html

>Last I wonder what would happen if you doped a MnO2 anode with a combination of Bi2O3 with SiO2 or TiO2, would you get the best of both worlds? A long anode life that can reliably make perchlorate?

It is good that you have a good anode, but the price of platinum precludes me from buying such an anode. That is a nice find!

[Edited on 24-12-2011 by gregkdc1]

michael faraday - 26-12-2011 at 15:24

I recently purchases a power supply, a 5volt 40 amp power supply. Where do i buy the clips that will attach the power cord that is attached to the wall to the power supply itself, the same goes for clips that will attach the cord that will go to my electrochemical cell??

dann2 - 29-12-2011 at 22:48

Hello Folks,

@Xenoid.
How do you attach an electrical connection to the Pt crucible?
I presume you flattened it out into some sort of sheet.
You can actually attach a piece of Grade 1, 2, 3 or 4 Titanium to Platinum (or MMO) by simply bolting the Ti to the Pt (or use a rivet). Unfortunately grade 1, 2, 3, 4 bolts will be almost impossible to find and Grade 5, which contains some Aluminium, will corrode away so you are stuck with the homemade rivet method.
A dude did this over on AmateurPyro and it works OK even though the connection was submerged in the electrolyte.

It's easy enough to track Perchlorate production by simply keeping an eye on Chlorate destruction with simple titrations. Titrations sound like one big pile of work but when you have some liters of solutions (Iron Sulphate and K Permanganate) made up, which will do many titrations, its only take about 10 minutes to do one titration. It will take less time if you do two at the same time.

@gregkdc1
http://www.oxidizing.110mb.com/chlorate/pyrochlor.html
Try Pyrochlores for Perchlorate if you are looking to do something new.

dANN2

hissingnoise - 30-12-2011 at 02:26

Quote:

I recently purchases a power supply, a 5volt 40 amp power supply. Where do i buy the clips that will attach the power cord that is attached to the wall to the power supply itself, the same goes for clips that will attach the cord that will go to my electrochemical cell?

I'm not quite sure what you're asking, michael - can you rephrase the question?

Mailinmypocket - 30-12-2011 at 07:57

I think what he means are alligator clips... Those are fairly easy to find at any electronics supply stores like Radioshack and I have even seen them in automotive supply stores too in the car electronics section sold for use as test leads.

See here:

http://www.radioshack.com/search/index.jsp?kwCatId=&kw=a...

hissingnoise - 30-12-2011 at 08:16

I always used crocodile clips to connect to 7/8" electrodes because they're big-jawed and strong!
If he's having trouble connecting his PS to the mains socket, he should probably go for a name change . . .

Xenoid - 30-12-2011 at 13:50

Quote: Originally posted by dann2

@Xenoid.
How do you attach an electrical connection to the Pt crucible?
I presume you flattened it out into some sort of sheet.

Hi dann2,

The electrode was made from a "scrap" 15-20 ml. tall form Pt crucible. I used "tinsnips" to cut a spiral 7mm. wide strip around the crucible, starting at the top rim. Obviously the first few cm. of the cut are tapered and this part was tightly twisted and rolled to provide the "lead in" for the main part of the electrode.

I cast some epoxy resin around this part using a short length of 6mm. plastic drinking straw as a mold. When I removed the straw (I should have left it in place) there were lots of bubbles in the epoxy and the surface was rough so I covered it with some glue-lined black heat-shrink tubing. This part is fitted through the cell lid using some plastic flanges and couple of "O"-rings. There is a tiny amount of leakage up the centre of the twisted "lead-in" but not enough to cause any problems.

The electrode in the image has an overall length of 24 cm. but the length of Pt is longer as it is spiralled. The weight of the original crucibe was about 14 g. and it was about 30 mm. wide at the top and 30 mm. deep. I was amazed how long the strip turned out. The electrode weighs about 11 g. as I did not incorporate the crucible base.

The electrode is probably worth about US$450 at current prices as scrap, given that assay, refining and commission needs to be paid.

dann2 - 30-12-2011 at 22:39

She's definitely a beauty!
I often thought that the Platinum-on-Ti-mesh Anodes are very expensive for the amount of Pt that you actually get. But since I have neither purchased nor used one it's only my perception.

Named?

Dann2

jpsmith123 - 31-12-2011 at 13:50

Wow that's a nice anode Xenoid!

(I've often wondered how well epoxy would hold up in a ClO3 or ClO4 cell. Apparently it's ok?)

BTW, has anyone yet tried electrodepositing Bi2O3, just by itself, over MMO (or anything else for that matter)?

I came across a paper (attached) showing that the face-centered-cubic form of Bi2O3...apparently the desirable phase...can be electrodeposited from a highly alkaline solution.

I also came across another paper describing an experiment where electrodeposited Bi metal (as nano-wires) was heated to 350 degrees C - which converted it into Bi2O3, also in the desirable form (paper attached).

Attachment: Bi2O3_From_Bi.pdf (502kB)
This file has been downloaded 2001 times

Attachment: Bi2O3_From_Alkaline_Solution.pdf (744kB)
This file has been downloaded 918 times

[Edited on 31-12-2011 by jpsmith123]

michael faraday - 1-1-2012 at 15:46

Quote: Originally posted by hissingnoise

Quote:

I'm not quite sure what you're asking, michael - can you rephrase the question?

I just bought a power supply, this one to be exact, http://www.ebay.com/itm/5V-40A-DC-Universal-Regulated-Switch...
I'm looking for the attachments that connect to it, like the clips that i screw into the connection board. or am i supposed to just tie the wires into it? does that clear it up?

Never mind, I just attached wires to the ports and that worked fine. If anybody knows though, is there a certain size wire that i need to use to maximize my power supply, which is 40 amps and 5 volts? Like right now I'm just using thin copper wire that was already attached to my alligator clips, thats whats attached from the power supply to the electrodes.

[Edited on 2-1-2012 by michael faraday]

hissingnoise - 2-1-2012 at 03:31

As long as their resistance doesn't heat them up, they're fine.
But it's best to have them at least as thick as those on the sec. winding . . .

hissingnoise - 2-1-2012 at 04:10

It appears not to have a thermal cut-out and I may be dense but what the fuck is a 'yawl', y'all?

hissingnoise - 2-1-2012 at 14:12

Quote:

The electrode in the image has an overall length of 24 cm. but the length of Pt is longer as it is spiralled.

Lucky you, Xenoid --- but do you not think it would be a better anode if it were beaten flat and polished (if necessary)?
And it might even be long enough to be halved and used as anode and cathode . . .

cosmos - 7-1-2012 at 18:01

Quote: Originally posted by dann2

Hello,

When we are controlling the pH, it is the pH of the bulk solution we are interested in. This is where 'chemical chlorate formation' will take place.
(We get no 'chemical chlorate formation' in the non pH controlled cell, only 'Chlorate made by electricity'.)
This is why, in pH controlled cell, it is best to have either a fairly large Anode/Cathode chamber (plenty of room away from the anode) for the 'bulk reactions' (chemical Chlorate formation) to take place or to have a second chamber for the 'bulk reactions' to take place.

Dann2

Can someone explain this better to me or lead me to a source that explains this? Thanks!

Pulverulescent - 8-1-2012 at 05:03

Quote: Originally posted by cosmos

Quote: Originally posted by dann2

Can someone explain this better to me or lead me to a source that explains this? Thanks!

What D2 is saying (in a somewhat (confusing?) roundabout way), is that in the anodic oxidation of chloride to chlorate, losses occur which causes the electrolyte to become progressively more basic over time!
Lower pH favours chlorate formation!

[edit] Household bleach has a high pH to stabilise the hypochlorite, preventing disproportionation . . .

P

[Edited on 8-1-2012 by Pulverulescent]

dann2 - 8-1-2012 at 12:07

roundabout way.........huh

"
What D2 is saying (in a somewhat (confusing?) roundabout way), is that in the anodic oxidation of chloride to chlorate, losses occur which causes the electrolyte to become progressively more basic over time!
Lower pH favours chlorate formation! "

NO. Havent said that.
Lower pH favours CHEMICAL chlorate formation. (nice but you must control pH)
If going the high pH route (no pH control) you are STUCK with 'Anodic Chlorate formation'.

The electrolyte becomes more basic because small amount of Chlorine escape from the cell untill pH goes to about 10 and Chlorine can no longer escape.
Read the link.

I am trying to explain what happens in a Chlorate cell and at the same time give some explanation (or definitions) to jargon that appears in the professional literature.
It is an explanation that will be suited to an amateur and not to a professional specalist chemist working in the industry.

Jargon like
'Chemical Chlorate formation' also called 'autooxidation' which is one of the (so called) 'bulk reactions'.

'Anodic Chlorate formation' also known as 'Making Chlorate by electricity' (this is very undesirable in industry).

See here for some explanation:
http://www.oxidizing.110mb.com/chlorate/reaction.html

If that too simplistic go to the further reading section of the page and have a great read.
If you cannot comprehend the explanation you need to study up on your chem perhaps.

'Free Chlorine' is another piece of jargon that gets thrown around.

On another note regarding the Tin Oxide / Bi Oxide Anode (baked onto Titanium), I cannot get it to work. When I bake the Ti with the precursor solution I just get passivated Ti.
I have tried Bi Nitrate, Bi Chloride (both home made and purchased). I have used Tin TetraChloride :5H2O and also the anhydrous stuff ( fuming liquid).
As soon as I add any Bismuth compound to the precursor solution I get a precursor solution that does not work. It's as if Bi is a poison. Don't know why I cannot get it to work as it has been shown to work both in patents and literature.
I etch with HCl, and intend to switch to Oxalic acid to see if that will make any difference (don't think it will).
I also intend to try adding some Nickle to the Bi/Sn Oxide precursor solution(as shown in a paper I obtained in ref. section) to see it that will work.
After a few more tries I will be giving it up FOR GOOD.

Dann2

[Edited on 8-1-2012 by dann2]

Pulverulescent - 8-1-2012 at 14:52

Quote:

If that too simplistic go to the further reading section of the page and have a great read.
If you cannot comprehend the explanation you need to study up on your chem perhaps.

Yeah, you're right D2, I'm just plain, bog stoopid!

But, sheeesh man, look on the bright side ─ no one will ever accuse you of being even slightly verbally constipated . . .

jpsmith123 - 10-1-2012 at 09:02

Hello Dann2,

I've been slowly acquiring some bismuth and tin chemicals and planning to do some experimenting...as soon as my present HV power supply project is done...and it is now essentially finished. (I had a bunch of potting compound that I had to use before it expired, and I finally did that yesterday...so I'm cleaning off my bench right now).

Anyway, the bismuth difficulties you're describing seem perplexing and very frustrating. But here's my question: As a practical matter, why not first try putting the Bi2O3/SnO2 on over MMO and/or over one of your experimental ATO anodes?

In my way of thinking, if, under the "ideal" condition of being an overcoat to something else, it fails to make ClO4 or doesn't adhere or wears away rapidly or something...then you can forget about it once and for all. If on the other hand it looks promising, then it may be worth further experimenting.

Quote: Originally posted by dann2

[...]

On another note regarding the Tin Oxide / Bi Oxide Anode (baked onto Titanium), I cannot get it to work. When I bake the Ti with the precursor solution I just get passivated Ti.
I have tried Bi Nitrate, Bi Chloride (both home made and purchased). I have used Tin TetraChloride :5H2O and also the anhydrous stuff ( fuming liquid).
As soon as I add any Bismuth compound to the precursor solution I get a precursor solution that does not work. It's as if Bi is a poison. Don't know why I cannot get it to work as it has been shown to work both in patents and literature.
I etch with HCl, and intend to switch to Oxalic acid to see if that will make any difference (don't think it will).
I also intend to try adding some Nickle to the Bi/Sn Oxide precursor solution(as shown in a paper I obtained in ref. section) to see it that will work.
After a few more tries I will be giving it up FOR GOOD.

Dann2

[Edited on 8-1-2012 by dann2]

dann2 - 10-1-2012 at 13:08

Hello JP,

Paper attached regarding Tin/Bi Oxide Anode + Nickle thrown in.
I have made some Nickle Nitrate from a pure (AFAIK) Nickle welding rod + Nitric acid which I intent to try.

I was thinking of doing what you said. Use MMO or perhaps a known Tin Oxide / Antimony Oxide precursor to form an anode (on Ti) and then start with some layers of Tin Oxide / Bi Oxide precursor.
I stuck with just using the Tin/Bi Oxide precursors so far (and just got passivated Ti)
Tin Oxide Anode are rather fickle. If you have not got the Ti SPOTLESSLY cleaned and etched you will not get a coat to form. If you use water to wash the Ti after etching that is not distilled you will NOT be getting a working coat to form. Found that out the hard way.
Perhaps I need a new clean pot of etching HCl but then again I tried making a Tin Oxide/ Antimony Anode during the failed attempts at trying the Tin Oxide /Bi Oxide Anodes and it worked OK, so it did not seem to be the etching acid or washing water.
Cobalt or Manganese Dioxide Anode seem to be much easier to make in that regard. Just paint and bake and you are there. They don't last terrible long (the Cobalt Oxide particularly) in a Perchlorate cell.

Dann2

Attachment: Characterization of Ni_Bi Doped Tin Oxide Electrodes_smaller.pdf (127kB)
This file has been downloaded 939 times

Pulverulescent - 17-1-2012 at 02:24

Quote:

The use of titanium in ruthenium oxide is very expensive.

All the PGMs and their compounds are expensive!
But Pt, if you want trouble-free synthesis of perchlorates, is the only suitable anode material!
Preparing PbO<sub>2</sub> anodes is messy, time-consuming, hazardous to your health and often produces poor results!
If your desired product is chlorate, gouging rods made of solid graphite (not compressed carbon) work well as anode and cathode!
I've never used metal cathodes, BTW!
There are cheaper gouging rods of polymer-bound graphite powder and these erode at an unacceptable rate and the polymer introduces lots of impurities into the electrolyte!
The problem is; both types look very similar and you won't know what you've got until they're running for about 15 minutes!
Heat-compressed pure graphite clouds-up quite slowly!

P

hyfalcon - 13-4-2012 at 16:23

Has anyone tried platinum leaf overlaid on gouging rods and bound with silver conductive epoxy?

dann2 - 14-4-2012 at 12:19

No

RonPaul2012 - 17-4-2012 at 04:40

Hey quick question.

For the best perchlorate cell what will I need ?

I know I need a platinum electrode but I'm not sure what the other one should be , could you please help me out I am in a hurry and don't have time to research.

How thick should the platinum plating be on a titanium electrode for prolonged life within reason of price ?

Thanks.

[Edited on 17-4-2012 by RonPaul2012]

stygian - 17-4-2012 at 08:12

electrolysis doesnt really seem like an option for someone in too much of a hurry to check google.

dann2 - 17-4-2012 at 13:40

Quote: Originally posted by stygian

electrolysis doesnt really seem like an option for someone in too much of a hurry to check google.

Styian, you are a very bold boy! (how's THAT for a flame).

@RonP
I guess since Nick Romney (hope I speeelt the name correctly) has kicked you backside off of the campaign (or should I say champaign) trail you should have more time for you other (much more useful) persuits.

Have a great read here:

WWW.OXIDIZING.110MB.COM

Dann2

RonPaul2012 - 17-4-2012 at 15:53

Quote: Originally posted by dann2

Quote: Originally posted by stygian

electrolysis doesnt really seem like an option for someone in too much of a hurry to check google.

I'm glad to know you guys care about America

It was time to go to work for me and I just got an e-mail from a chinese supplier asking about Pt thickness and since I have no idea about thickness I ask you guys.

BTW thanks for the link

[Edited on 17-4-2012 by RonPaul2012]

dann2 - 18-4-2012 at 05:13

The thicker the better and the more expensive it will be.
All industrial setup's will use Platinum clad Anodes (AFAIK). The Pt is not actually plated onto the substrate as you can only apply relatively thin coatings of Platinum to stuff before it starts to flake off (internall stress or something like that). If you want to make an Anode with a thick coating of Pt (say a half MM) you must actually clad a substrate with the stuff. Copper and Valve metals can be used as the substrate.

The Pt coated (plated) Anodes that you will buy will work no doubt. Try to keep all Chloride out of the cell to make it last as long as possible. Make Chlorate with Carbon or MMO. Save the Pt for Perchlorate.

What is the picture of?
The Moderators Lounge perhaps?

RonPaul2012 - 18-4-2012 at 15:09

Quote: Originally posted by dann2

The thicker the better and the more expensive it will be.
All industrial setup's will use Platinum clad Anodes (AFAIK). The Pt is not actually plated onto the substrate as you can only apply relatively thin coatings of Platinum to stuff before it starts to flake off (internall stress or something like that). If you want to make an Anode with a thick coating of Pt (say a half MM) you must actually clad a substrate with the stuff. Copper and Valve metals can be used as the substrate.

The Pt coated (plated) Anodes that you will buy will work no doubt. Try to keep all Chloride out of the cell to make it last as long as possible. Make Chlorate with Carbon or MMO. Save the Pt for Perchlorate.

What is the picture of?
The Moderators Lounge perhaps?

I had some time to look over the link you sent me and it says that PbO2 is the "HOLY GRAIL" of anodes , I am a little skeptical of this because I have heard from almost everyone that Pt is the best , but I went ahead and contacted a supplier of PbO2 anodes anyways .

I have a "problem" of not wanting to start projects until I have acquired every last thing I need to start , I guess in the long run a little ( a lot ) of planning is a good thing

Btw the picture is of the redoubt defenders at the Battle of Bunker Hill ; cool picture eh ?

[Edited on 18-4-2012 by RonPaul2012]

White Yeti - 20-4-2012 at 13:29

I'm sorry to interrupt this fruitful discussion, but did anyone look into "glassy carbon" as a potential material for anodes? I'm not sure if it's cheaper than platinum, but it looks like a nice alternative to the lead dioxide/ ruthenium/ MMO nonsense that has not been successful to any extent so far.

barley81 - 20-4-2012 at 15:07

Yes, this has been discussed here on the forum. Use the search engine. Someone used it in a chlorate cell.

dann2 - 20-4-2012 at 16:52

Garage chemist has tried the stuff in a Chlorate cell.
He is getting around to trying it in a Perchlorate cell.

garage chemist - 20-4-2012 at 17:11

http://www.sciencemadness.org/talk/viewthread.php?tid=15345

The glassy carbon anode erodes visibly in a chlorate cell, though in a completely different manner than graphite. Little particles (0,1-1mm) are spalling off the anode and collect on the bottom of the cell, but the cell liquor stays entirely clear.
I haven't yet analyzed the cell liquor, for lack of a real good procedure. It's still standing around on my shelf.

jpsmith123 - 6-5-2012 at 13:50

Here's some "bedtime" reading material; "Mechanism of Oxidation of Chlorate to Perchlorate at the Platinum Anode".

http://www.dtic.mil/dtic/tr/fulltext/u2/079372.pdf

hyfalcon - 29-5-2012 at 15:06

That's been posted somewhere else. How do I know? I already have a copy of it in my black hole.

Swede, here's a picture of my lasarred electrodes laying on top of the .25" titanium plate grade 2. I'll ask here, is there any reason to not use a single piece of the plate cut the same size as the two anodes of mmo sandwiched between the mmo? Then run the mmo's co-axially or I should say in series. Will that be enough cathode area do you think?

[Edited on 29-5-2012 by hyfalcon]

Titanium plate with mmo anodes resized.JPG - 61kB

[Edited on 29-5-2012 by hyfalcon]

Swede - 30-5-2012 at 07:18

You have a power supply capable of pushing juice through those? Wow! What kind of current densities are you looking at?

Remember, the rate at which oxidation takes place is dependent upon current and pH, not necessarily electrode area. 50 amps through a 4" X 6" anode makes the same chlorate as through a 12" x 12" anode.

Anyway, I am intrigued by the scale you are going for. I personally like to sandwich electrodes, normally two cathodes surrounding a single anode. 1/4" thick Ti is huge overkill for thickness... the cathode is protected and does not erode. You could get away with 0.06" Ti with ease. But the 1/4" stuff would work fine.

If you use ONE cathode with two anodes, it'll work, but your effective anode surface area will not be as good as it could be. I'm guessing the current flow from the far side of the anode isn't much compared to that portion facing the cathode. With your massive anodes, I'd take one of them, cut the ti sheet into two pieces, and sandwich the anode with them.

Another option I've often wanted to try is have a Ti cell welded up, and use the entire cell as a cathode. But that's some big $$ for the Ti.

I'd love to hear more about your apparently enormous setup!

hyfalcon - 30-5-2012 at 13:41

My power supply is a dual output 200A constant current or switch to constant voltage, whatever floats your boat. I haven't quit settled on a reaction chamber yet, but I'm leaning towards a 6.5 gal plastic bucket with a screw top o-ring sealed lid. Cutting this .25" plate down to size is the next hurdle to surmount. That's a 13.75" square plate by the way. I got it off ebay for 25.00 plus about 18.00 shipping. They have more if you want to do a massive titanium welding project

These things would make one hell of a Captain America style shield except for it being square instead of round. Might make a good insert for a kevlar laced fiberglass buildup on top of it....

I picked the power supply up off ebay. No one seems to know what brand it is or much about where it was manufactured. If anyone recognizes something in these pics, let me know. This is all the description I got for it:

Mode 1&R 0-50V Dynamic Load: DC 120/1KHz Current Range: 10A, 50A, 100A, 200A This item does not have a Manufacturer, Model or Serial no.

Once I get the lab set up, I hope to run the chlorate production on one side and the perchlorate production on the other side. I think I'm going to have to look for a larger reaction chamber or set up multiple chambers like you had going.

@ Swede, I been meaning to ask you, on your KClO3 rig you had going with the carbon electrodes, What did you use for the actual mechanical connection to the carbon electrode? I've been scratching my head on that one.

[Edited on 30-5-2012 by hyfalcon]

[Edited on 30-5-2012 by hyfalcon]

[Edited on 31-5-2012 by hyfalcon]

[Edited on 31-5-2012 by hyfalcon]

[Edited on 31-5-2012 by hyfalcon]

dann2 - 31-5-2012 at 05:43

If you take off the cover you might see some manufacturer name or model number?

hyfalcon - 31-5-2012 at 17:38

Took the top off and there is no identifiable marking of any sort. The hunt continues.

Swede - 14-6-2012 at 09:37

It looks like a dual supply. Is there a wattage placard? That'd speak volumes about what sort of energy the unit can deliver to a cell. Dumb question, what is the input voltage? Usually something of that capacity will do 240V one or three phase. If you can do 0 to 10V and 0 to 100A then you're golden.

I personally never have used carbon or graphite anodes, so you may have me confused. I know dann2 has used them extensively.

One thing to keep in mind with that monster is the relatively poor conductivity of titanium. Without an adequate shank cross section, you're going to get some serious heat output. I've seen probably 250 degrees C at 70 amps on a titanium shank that measured 1mm x 25mm. This of course can melt plastics with ease.

I use #4 Cu welding cable and crimp-on connectors like this:

Another way to do it is to use an aluminum block that clamps onto a rectangular strap section. In this one, I bolted a big surplus heat sink onto the Al block. The Cu cable connector goes right onto the stainless steel stud (via nuts) embedded in the block. This setup works well because it is adaptable to any number of Ti strap dimensions, and no hole needs to be drilled in the Ti.

Added: Have you considered lead or tin filled tubular shanks? These are superior for a number of reasons. They can be mounted via an appropriate PVDF (kynar) compression fitting drilled through for the outer diameter of the tube, and the big one is that the filler metal, Pb or Sn, carries the current rather than the titanium.

To make one, you heat a Ti tube to dull red, and pinch one end into a flat. This can take 3 or 4 steps as the Ti work hardens, and if you rush it, it'll crack on the edges. But once the end is flattened, you fill the tube with molen metal, then drill and tap the end for a stud. Onto this goes a standard Cu crimp connector, like so:

[Edited on 14-6-2012 by Swede]

hyfalcon - 14-6-2012 at 19:08

It's a dual output, 200 amp 50v max power supply.

Here's some anode porn for you!

I just picked this up off ebay. Blasted thing is 20in. long

Now I really do have to find that stainless steel 55gal drum or maybe this will work?

Code:

http://www.ebay.com/itm/Stainless-Steel-Drum-Barrels-/300606246444?pt=LH_DefaultDomain_0&hash=item45fd874e2c#shId

[Edited on 15-6-2012 by hyfalcon]

dann2 - 15-6-2012 at 03:25

What is the Anode made from and what is is meant to be used for?

hyfalcon - 15-6-2012 at 05:22

It's a clad platinum tip about 9in long used for corrosion abatement. Total length is 22in.

gregkdc1 - 27-7-2012 at 12:52

Here is a thought for an anode that I don't think anybody has tried at least from what I have read. Usually there is a good reason for why something like this wont work so if you are inclined to tell me why it won’t work please be gentle. Anyways I read a patent that was talking about using manganese dioxide that has a little silicon dioxide added to the oxide layer to reinforce it. I was really excited about trying this until I realized how hard it could be to get the silicon precursor chemicals. I also read how lead itself will make perchlorate from the lead dioxide that is formed on its surface all be it extremely poorly because the oxide flakes off. Then it hit me has anybody tried alloying metals of say manganese with a little titanium or tin/lead/silicon to make an anode? The idea is that you make a solid metal anode that forms the conductive oxide coat when placed in a perchlorate cell, but you change the chemistry so the oxide coat adheres well to the anode and is stable? One obvious benefit would be if the layer flake off or got damaged it could heal itself.

Swede - 30-7-2012 at 05:37

^^ The problem with your scenario if I read it correctly is that any sort of "self-healing/plating anode" isn't going to adhere, it'll simply form dust or solubles that don't stick well. And besides, the chemistry of chlorate/perchlorate electrolysis is entirely different from that of a plating tank.

I have not experimented with Mn/oxides in any form with this process. I am unsure whether it will work. Anyone know?

Arcuritech - 22-8-2012 at 19:19

What about metallic crystalline Boron? Silicon was mentioned in the first post, and that also might work. Fortunately for me I have both of these things, I'll have to test them out next time I'm in my lab.

White Yeti - 28-8-2012 at 08:14

What about using polythiazyl as an anode material? This has already been discussed in several small threads that I will not cite. But discussion has died down very quickly, perhaps because of the dangers associated with making and handling S₂Cl₂. I would like to present a different synthesis route for S₄N₄ (the precursor to polythiazyl) involving liquid ammonia and solid sulfur instead of S₂Cl₂ and gaseous ammonia:
10S_(s) + 4NH_3(l) —→ N₄S_4(s)+ 6H₂S_(g)
Source:
Handbook of Inorganic Chemicals by Pradyot Patnaik

The S₄N₄ can then be reacted over silver metal to yield its polymer.

Does anyone have information on the electrical conductivity of this polymer and/or its chemical inertness?

elementcollector1 - 29-8-2012 at 21:35

I have something interesting to contribute, and I WILL share it with you!
While electrodepositing manganese metal from it's aqueous chloride, I noticed that if too much current is applied to the solution, or only one cell of electrolysis is used, the cathode will receive a firm, strong deposit of MnO2, resistant to flaking and such. Chlorate anode? We'll see.

It wasn't exactly what I wanted at the time, but I thought it might be useful to you.

offset442 - 22-10-2012 at 08:41

I have recently come to interest in this type of anode, and while exploring the "ironage" iron mine near twenty nine palms, ca. I now have some very large massive chunks of hydrothermal generated natural magnitite, and a few small slabs of very well formed massive crystals hammered off a monolythic rock the size of a car. I currently looking for someone that has a diamode saw with a feeder co I can cut some nice slabs, considering that I have an unlimited source of this material it has not peaked my inteast, also iron mines are very common, I bet a lot of ppl live within reasonable distance fro one to pluck chunk of out magnatite of a near by wash. Just an idea.

Swede - 30-11-2012 at 06:54

JPSmith, have you pursued the Bi Pyrochlore at all that you posted on page 40 (Aug 2011)?

I have been re-reading those patents, and I think there's some potential, even if it involves Ru.

RuCl3 hydrate can be had for moderate prices... I was quoted $8 per gram from one Chinese source. I did manage to pick up 25 grams of the chemical.

I'm wondering if the pyrochlore configuration is necessary for success with perchlorates. I suspect it does, but I am tempted to simply modify a Beer procedure with the addition of Bismuth.

As I mentioned in another thread, I am gearing up for a massive effort in MMO creation. I have prepared Ti strips, and gathered up a list of reagents:

Bi(OH)3
RuCl3
T-butanol
PdCl2
SnCl3
MnSO4

And the necessary mineral acids to make it all hopefully work. I have a good furnace that can do 1100C if needed, although all of the Beer patents use a much lower temperature.

Both Bi(OH)3 and RuCl3 can be easily turned into the appropriate oxides per the pyrochlore patent, but the obvious question is how can this material be attached to a valve metal with any success.

I wonder if Bi ions, if added to the typical Beer "paint", then fired at extreme temps, would form a pyrochlore or some sort of solid solution which would be catalytic to oxygen and perchlorate.

Swede - 30-11-2012 at 07:55

I may have mentioned, I am working on a document regarding electrochemistry as applied to chlorate, perchlorate, lead dioxide plating, etc., trying to gather together into one place as much knowledge and practical experience as possible. It's over 200 pages now, but not yet complete due to lack of practical perchlorate processes that don't use Pt.

Anyway, one of the things I did was create worksheets for two of the most common questions a beginner has...

1) How long do I run my cell?
2) What was my CE (Current efficiency)

They are based upon KCl. The numbers need to be switched up a bit for NaCl.

There was a guy on another forum who had some questions on this and I created a separate download with these worksheets. Maybe some guys will find them useful.

Worksheets

elementcollector1 - 30-11-2012 at 19:35

Ooh, I want that 200-page report! Would be incredibly helpful, as I'm just starting on my journey of producing perchlorate (I have a small platinum wire as an anode).
Both of those questions you mentioned are always vexing to me, I would love to see them answered!

Swede - 1-12-2012 at 07:10

Download them! There is a link in my post.

Here it is again... Length of Run and Current Efficiency (KClO3) Worksheets

Note again this is for KCl electrolysis. Until you know your efficiency, you have to estimate for the length of run. If you are executing quality pH control, and maintain close to 6.8, then your efficiency might be 80 or higher. With NO pH control, efficiency is probably close to 50%.

Efficiency drops as chloride concentration decreases. I've noted with MMO at least that below about 5% chloride, efficiency drops dramatically.

A saturated solution of KCl at typical ambient temperature is about 15% to 16%, so use that as a starting percentage unless you heat your solution to dissolve more KCl. So a typical run would go from 16% to 6% chloride.

Some excerpts:

For no pH control and an estimated 50% efficiency, using conservative ending chloride %

Quote:

Extremely basic Run-Time Rule of Thumb for a cell operating at 50% efficiency:

Ampere-hours = Cell Volume (Liters) * 360

Quote:

Predicted yield: Regardless of the CE of your cell, there is a simple rule of thumb for the approximate yield from a potassium chlorate cell. As mentioned, and reproduced here for your convenience, for a given liter of electrolyte, each incremental reduction of chloride by 1% (i.e. 12% Cl- to 11% Cl-) will yield 35.7 grams of KClO3. A typical cell, run from 14% Cl- to 8% Cl- should yield ~214 grams per liter of potassium chlorate. Ten liters, therefore, yields 2,140 grams; 2.14 kg. The dry weight will be somewhat less, as much of the KClO3 will remain in the used liquor for recycling into the next run.

If you are running a sodium cell, ignore everything I've said. Ampere-hour requirements for sodium chloride are different, and there is no solid to be harvested until the liquor is displaced with KCl.

It's controversial... many prefer sodium because it is more soluble than potassium, but I want no sodium ions in my product, and I find that being able to harvest crystals directly from the cell to be a benefit. Lack of solubility can be made up for with cell volume. As noted, you can harvest several kilograms from a 25 liter cell. Given a good wash, the product will be about 99% KClO3, and 1% KCl. If you need better than that, KClO3 is easily recrystallized.

elementcollector1 - 3-12-2012 at 18:09

Hey, quick question: I have a tiny 1" Pt wire that I'm thinking of using as an anode, but I'm concerned about the difference in size to it and another cathode, and how this will affect cell efficiency. So, given that I plan on using a stainless-steel spoon as cathode, should I use a spoon-sized MMO-titanium anode or the wire-sized Pt anode? I can make an MMO anode if that's what I need, but if platinum wire works just as well, I don't see why I should bother.

Swede - 5-12-2012 at 08:36

IMO, cell efficiency is the least of your worries. The effective surface area of your wire is going to be very, very small. I assume you are doing a small benchtop setup for fun, because you are not going to get much product, mass wise, unless you allow the reaction to run a LONG time.

Pt will oxidize Cl- ions all the way to perchlorate, ClO4- but most of the time, it is reserved for only the chlorate (ClO3-) to perchlorate (ClO4-) process, because chloride ion does indeed erode Pt. So does the chlorate --> perchlorate path, just slower.

Your current is going to be, must be, very small with an anode that size. 200 mA per square centimeter would be appropriate. Too much current, and you are going to lose that Pt. For a cathode, your best bet would be a piece of titanium or stainless steel wire. If you don't have those, look for a long, thin, stainless wood screw at the hardware store. Or... use the spoon. Current density on the cathode isn't as important as the CD at the anode.

Applying current to such a tiny piece of wire is going to be tricky. The connection, unless you weld the wire, probably needs to be above the electrolyte level, losing still more anode surface area.

White Yeti - 1-6-2013 at 08:13

I apologise for bringing up an old thread, but I had an idea for a potential anode material.

What about using a titanium electrode coated in titanium disulfide (TiS2) as an anode in a chlorate cell?

One weakness of this electrode would be operation in acidic medium. From memory, a chlorate cell operates best at pH 6, so this should not be a significant problem.

Titanium (much like lead) cannot be oxidised past +IV, so this electrode material should hold up to a highly oxidising environment.

Does anyone think this idea is plausible? I would try this myself if I had a suitable furnace.

papaya - 2-6-2013 at 10:08

Where it is used, I never heard about such anode?

White Yeti - 3-6-2013 at 12:00

The point of experimentalism is to try new things based on plausible ideas.

PbO2 anodes, MMO anodes, and platinum anodes have been beaten to death, it's time for something new, anything new, even if it may end up being wrong.

I hypothesize that if an etched titanium electrode is heated in a suitable* furnace in the presence of sulfur during a suitable* length of time, the resulting titanium-sulfide-on-titanium-electrode would be both conductive enough* and resistant enough* to be used in a chlorate cell.

*experiments are needed to determine these parameters.

papaya - 3-6-2013 at 12:48

Completely agree with you White Yeti, I just said that I never have heard about that compound in the past (and also it's electrical properties). Another things that may be ''new'' is TiN - golden coating on some instruments, it's also conductive and all you need is Ti+N2 reaction (in powdered form it's quite an exothermic reaction, so SHS synthesis is possible(available?) on this), but I highly suspect it's not inert enough to work as an anode in brine.

White Yeti - 6-6-2013 at 18:16

Titanium nitride could be a viable alternative, although I wonder if it would be truly impervious to flaking and oxidation. Then again, there is no way to tell whether or not an anode material is susceptible to flaking during operation.

Now that I think about it, a TiS2 anode could be susceptible to flaking as well...

papaya - 7-6-2013 at 06:37

Only two ways from that point: trying to find out related information or the experiment must be carried out. Search in this forum (maybe even in this thread), there I've seen once a paper (some ''top secret'' of the past) which contained info on TiC, etc, etc.. (I couldn't find now to provide link).

batsman - 30-7-2013 at 06:22

Somebody knows where you can buy graphite sheets to use as anodes. I have googled it, and searched on ebay, but i havent found anything.

Have a great day, guys!

Xenoid - 30-7-2013 at 12:02

batsman - clearly you didn't try very hard!

Several years ago, I bought graphite anodes from the Graphite Store! The freight to NZ was more than the cost of the graphite, but the product and range was good as were their prices.

http://www.graphitestore.com/

violet sin - 11-10-2014 at 01:46

nothing really new I guess, but I made a crappy spot welder and tacked some titanium wire to both mesh MMO and plain sheet, as a resistant support for the working plates. I haven't even finished the spot welder yet, used a rubber mallet to hold down the floating electrode and moderated power with turning on and off the power strip it was plugged into. super ghetto I know, but I just wanted to see if it could be done on an "I don't have all the time in the world" mock up, with improvements to come. I have a variac I'm not using yet, as well as all the materials to make a nice one with variable power. but for now here are some pics

1)you can see the size wire I used for the 1-1/2 wrap
2) front of the transformer
3) tacks on plate and two mesh MMO pieces
4) close up of the spots
5) another close up

they seem physically OK, not super strong, but short of TRYING to tear them off the Ti wire wasn't going any where. survived 3 increasing tweaks with out snapping. how they perform chemically is another thing. I only flattened out an edge on one of the wires, which mean the other two have less surface area meeting, which was also really hot in standard atmosphere ( no O2/N2 shield of any kind used ) so it may make a nifty lill cave for gas generation from weakened titanium, may be fine.

on my first try with two wire pieces, it got hot, then blew out. after cooling it looked like the heart of the two wires shot out through two volcanic craters ( tiny ones, but half the depth of the wire)

fun learning experience, now it's time to make a sweet lever arm to reliably spotweld. .... and figure out how to bend the Ti plate at a 90'<, every time I do it snaps just prior to 90'. but I wanted to make support strips similar to what is seen in a pool electrode stack. because I am actually trying to use this for my pool.

-Violet Sin-

hyfalcon - 11-10-2014 at 03:40

You need expanded mesh titanium. It takes to being bent better than solid sheet. I've gotten right at 330 degrees without it breaking.

Superscripts don't seem to be working.

Little Ghost, Look at his MMO mesh. You should be getting 2 pieces
of the same size in the Post shortly.

[Edited on 11-10-2014 by hyfalcon]

[Edited on 11-10-2014 by hyfalcon]

violet sin - 11-10-2014 at 05:27

I had looked for the bare titanium mesh, but couldn't find any in my price range for this project. probably would have had a hard time ordering such a small amount as well.

what I ended up getting 2 @ 6.75" x 10" MMO mesh from laserred, and 8 @ 3.125" x 8" x 1/16th plate from ebay. I also have a dwindling supply of ~3mm wire welder Ti purchased a few years back( soo many electrodes were made). the metal is a bit tough on tools, I'm not set up with a metal working shop. that was immediately apparent. I purchased more than I need, so several attempts could be made. some of the plate is to be cut up for support of the small stack that will be built.

but I am quite pleased with the spotwelder capability, and have already cut and drilled two steel pieces for the electrodes as support plates for the copper so I can apply some force with a lever. it gets hot quick and increased force will allow for a stronger bond with less discoloration, from what I am seeing. as it is, I was using multiple quick 1-2 sec heating. at least the oxidation stayed localized. also noted, after messing around with it for 20 min off and on accessing its capabilities, it( the secondary) was only slightly warm and the core was still cold to the touch.

papaya - 10-2-2015 at 14:24

A question about "standard" MMO pool chlorinating anode - recently I got some from very well know *bay seller, but what I got raises few questions to me.
first - it has some rust-colored spots on the surface, also it's not completely dark and has even golden-copper red tint on some sites - is this normal or the anode is already hard-used?
second - I tested it in a NaCL solution at LOW current densities (about 0.5A on 5cm2 and 3.9V) - surprisingly after some time it still works(electrolyzing), but now I have some orange stuff floating on the surface of water, and since the cathode is made of high quality titanium - it comes from MMO anode. I changed the solution with a fresh one - and once again after few hours of electrolysis some orange-brown stuff is floating on top! Is this anode wearing out or what? I thought MMO is really rough stuff, what is going on???

Metacelsus - 10-2-2015 at 14:38

Sounds like iron(iii) oxide. Are you sure the MMO substrate is Ti for your anode? I would suggest testing your crud for iron.

papaya - 10-2-2015 at 14:52

The substrate stays unaffected since I can see from sides (where it was cut) - most likely it's titanium, magnet doesn't act on it. So far I don't see any major damage also to coating, but that brownish crap collecting on the top makes me think it's degrading! :mad:

Coating must be RuO2 based, not something like Co oxide, isn't it? In the past I was experimenting with self-made Ti/Co3O4 anodes, which were not very stable and were degrading like this (if it's really degrading)one giving out floating stuff, is it possible that I got Co3O4 anodes instead of RuO2(do they exist in the market?)?
I just really want to listen to everybody who worked with MMO what they think on this issue, please..

papaya - 11-2-2015 at 00:55

After 12 hours of electrolysis there was not only orange junk floating on top, but also some white fluffy stuff floating in the liquid. Sh*t! After that I started with a fresh NaCL solution third time and already after half hours there's that same orange thing appearing! Of course I don't use distilled water as a solvent - just plain water and table salt, but this cannot be the problem, isn't it? Somebody say something, I'm quite disappointed.

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