Cobalt Oxide Anodes

Thanks for the information on solvents!

The chlorate is not my first, but all the previous chlorate was produced with graphite rods. This is my first chlorate with a Ti anode...

Yes we are all well aware of that particular layering scheme .
No news for us there .

Has your work ever inolved cobalt - nickel spinel at the Ti ,
as an added interface ? ( With everything else the same )

For example:
Ti/Co2NiO4/SnO2+Sb/alpha-PbO2/beta-PbO2

@ Xenoid , that "peacock blue" dust free material
and coating you have there may not quite be there yet
for ClO4 , but it just might happily make ClO3 till hell freezes ,
(if porosity isn't there) , so it might be fine for chlorate ,
I don't know . Anyway that color development is very interesting , because the single spinel is black and so is the
single MnO2 , and black plus black isn't blue , unless something *very interesting* has occurred like a
bimetal spinel of Mn and Co , even though you did not
mix the two precurors , a solid solution migration must have occurred from the underlying cobalt spinel layer , by diffusion
at high temperature , the two different layers merged and
reacted to form the bimetal spinel . And because the shamrock patent described the mixture of Mn and Co precursors as useful for two of the parts of a ClO4 selective
mixture , then the bimetal spinel might be headed suffciently
in the right direction to at least make a good chlorate anode ,
even if it stops short of the ClO4 capability for lacking the third element . Anyway , it's a pretty color so even if nothing else it would be good as a decorative finish

[Edited on 14-12-2007 by Rosco Bodine]

Indeed!
Thanks to Alembic (my hero ), we are aware of it. Took a bit of hammering home though.
NONE of us in here has *actually* manufactured a working anode of this scheme yet though (apart from yourself R.P.). That's a very important point.
I am at the DTO stage only, currently running a DTO Anode in a Perchlorate cell.


Keep up the good work all.

Dann2

[Edited on 14-12-2007 by dann2]

4 - Coat Anode - Chlorate Cell

Hello,

Firstly, regarding mini-batteries:
Looks like the simple way around that problem is to use the anode twentyfour, seven, 365

I have seen the gold coating, (failed anode in Perk. cell) with naked eye and looked at it with microscope. I guessed at the time it was Co Metal (bullshit??? probably). Is certainly looks like metal but Cobalt is not gold coloured but silver grey AFAIK.

I must confess I only got around to setting up my Co Oxide anodes this morning. They are going now for about 12 hours.
The anode have cathode on both sides. Two cells are in series with a PSU power supply + resistor. Chlorate cells.
Current density is higher on one anode as it is smaller.
316 and 150 approx mA per square cm.
Voltage accross cells similar @ 3.8 volts.
No problems to report yet.


Still have not set up the Li Perk. cell using DTO Anode

Dann2

@Xenoid

There may be a problem with having a cylinder form anode
horizontally oriented the way you describe because you can't get an even current density across the surface .

The high spot closest to the cathode gets "scorched"
in the noontime sun while the backside freezes to death at midnight , and every other point gets something
of an average value of current density in between the
two extremes . Much better would be to have a coaxial
arrangement of cathode rods maybe 6 or 8 , and put
the anode right in the center , so the current density
is more evenly distributed across the surface . Do that
and it should last way longer and operate way more efficiently .

[Edited on 14-12-2007 by Rosco Bodine]

Sherlock and Shamrock

4 - Coat Anode - Chlorate Cell

My God.... the Co Oxide Anode thread was in danger of dropping of the bottom of the "Today's Posts" list...

Thought I better post something, the cell is still running after 9 days, current has now dropped to 1.71 amps.

This Co oxide spinel is pretty tough stuff!

Hello,

Regarding the 'Old Chestnut' US2564707, the enclosed doc.
is illuminating for the resistance measurement that they are doing on the DTO.
I was inclined to think that the resistances shown for the different %'s of Sb were rather high.
They are not. The patent mesures the films 'in squares' end to end (as it were) as opposed to 'through' the films (the thin way).
The actual resistace 'seen' by the current going from an anode is very very little little. Have not had time to figure it out but an acutal figure on the RESISTIVITY of actual bulk ATO for different Sb % would be nice.
I propose the following table for resistance seen by 200mA of current coming out through (as it were) a DTO film
Sb = 1%-------------------> Resistance = SWF
Sb = 9%-------------------> Resistance = Slightly more that SWF
Sb = 18% -------------You get my drift.

The patent also states that a high Sb content is needed for
to keep the coat from degenerating when the coating is thich. (Anode coats are thick).
page 5 col 6 line 0

Another reason for high Sb in *Anode* coats may be to give the anode coatings a more favourable
higher O2 and/or lower Cl2 evolution protential.
(as per the Bi2O3 in SnO2)

Dann2

[Edited on 16-12-2007 by dann2]

[Edited on 16-12-2007 by dann2]

@ Rosco - I imagine you as the hirsutely challenged person on bass....

I recall being devastated when Simon & Garfunkel split up....
How old am I...?

[Edited on 16-12-2007 by Xenoid]

Hello,

and regarding the old well proven Lead Dioxide coat that will always work????????
That's the problem, ye old LD coat in *Amateur* circles has been a total failure IMHO. Sweet dam all people that I know of have got it to work on a long term basis. Hopefully the DTO on Ti will change that.
Hope I am not insulting anyone here but LD up to this point has been a washout and I am talking about the last 10 years, not the last 6 months.
How old is THAT.

Dann2

@Xenoid
I felt the need to have a cool breeze blow through and leave some extra cool across this page before I blow my own Paul Simon seemed appropriate to the moment .

@dann2 , I get the impression there's nothing I can say here to get you to put together other information that
is well established , from sources beyond the few patents you seem to favor investing confidence as some singular truth , to see the larger picture and draw your own conclusions . You are on a bandwagon there and along for the ride to wherever that confidence (bias) takes you .
There's different ways I have tried to cover this topic and provided references , but none of it registers with you as relevant , so you want to argue the relevance . I don't . It distracts me from working the problems I recognize which you are certain don't exist , because we aren't even on the same page concerning ATO , how it works , proportions , precursors , interpreting measurements ,
expected color indicators, ect . And when I give a valid
explanation which will withstand scrutiny you dispute it
not because you have different information but because
you believe having a different opinion somehow trumps
the data that tells a different story . This really becomes
tiring and frustrating and distracting .

I have no particular preference or bias and simply want
to go where the data leads in indicating higher art .
You act like there is some personal investment you have
which makes that somehow threatening , and that could only be because you have closed your mind and zeroed in on one possible solution you think is *it* like there is
only one way to do this .

And just because your own experience with PbO2 has not been good doesn't mean that PbO2 isn't still the best
and most technically simple solution even if it requires
precisely controlled conditions to do right . If you will
get off this little ATO crusade and let the experiments
proceed in peace , then maybe a solution can be worked out that is more user friendly if not truly idiot proof .
A plausible process was worked out for massive PbO2
and that was no good , too complicated ....so what's
your solution, Titanium substrate , yeah boy that's it .
Just didn't notice that Ti is an exotic material and making use of it requires higher tech than what was causing failure and problems for the PbO2 ? And now you still
likely have the PbO2 to deal with , only now it has a
high tech prosthesis for a backbone . Well damn if
folks just can't hack the massive PbO2 on iron in the
garage , lets fix that technical handicap by adding
complexity two magnitudes greater , and then bitch and whine incessantly about why it should be more difficult .

Let me ask you , are you enjoying playing a troll here
and continually shitting on good data ?

Why don't you go buy yourself a pound of platinum
instead of staying at me for a pound of flesh , because
in the world of technology I am an apex predator .

Quote:

Originally posted by Rosco Bodine @Xenoid I felt the need to have a cool breeze blow through and leave some extra cool across this page before I blow my own Paul Simon seemed appropriate to the moment .

Try the pills and Absolute ethanol, always works for me
You'll be looking for them after listening to that shit, .................(ONLY JOKING).

Cloth substrate anode
It is illuminating to note that no major manufacturer have touched massive LD Anodes for the past 40/50/60 years with a forty foot bargpole.

I shall purchase my Ti, not make it myself
The idea (as pointed out to you a long, long, long time ago here
http://www.sciencemadness.org/talk/viewthread.php?tid=2465&a... ) is that Ti is self healing/ self sealing. Hopefully (that's hopefullly. It may not work) less demanding Lead Dixode plating conditions will produce workable, repeatable anode(s), it may not. Your opinion is that they will not work (the Ti substrate ones). I intend to try.

Quote:

Originally posted by dann2 Hello, Quote: Originally posted by Rosco Bodine @Xenoid I felt the need to have a cool breeze blow through and leave some extra cool across this page before I blow my own Paul Simon seemed appropriate to the moment . Try the pills and Absolute ethanol, always works for me You'll be looking for them after listening to that shit, .................(ONLY JOKING). Quote: Originally posted by Rosco Bodine @dann2 , [snip] you are certain don't exist , because we aren't even on the same page concerning ATO , how it works , proportions , precursors , interpreting measurements , My bottom line on the information for DTO for anodes is that I am much, much, much more inclined to follow DTO information that is presented in Anode patents, as opposed to DTO information regarding applications for making resistors/conductors on glass and other non conductive substrates and other time consuming speculation.

What stannates ? Are you speaking of the ammonium derivatives . And are you saying that the problem was in making them or that you made them okay but in trying them they would not work ? Anyway many of the dopants in
the SnO2 are believed to exist in the form of stannates .
There is some basis in chemistry for that belief , so the the
extent that some of your Sb is in solid solution with SnO2
you may have to that extent actually made *that* stannate work , even if the other two from an ammonia solution were a problem

Quote:

Quote: Originally posted by Rosco Bodine A plausible process was worked out for massive PbO2 and that was no good , too complicated ....so what's your solution, Cloth substrate anode It is illuminating to note that no major manufacturer have touched massive LD Anodes for the past 40/50/60 years with a forty foot bargpole.

Quote:

Quote: Originally posted by Rosco Bodine Titanium substrate , yeah boy that's it . Just didn't notice that Ti is an exotic material and making use of it requires higher tech than what was causing failure and problems for the PbO2 ? And now you still likely have the PbO2 to deal with , only now it has a high tech prosthesis for a backbone . Well damn if folks just can't hack the massive PbO2 on iron in the garage , lets fix that technical handicap by adding complexity two magnitudes greater , and then bitch and whine incessantly about why it should be more difficult . I shall purchase my Ti, not make it myself The idea (as pointed out to you a long, long, long time ago here http://www.sciencemadness.org/talk/viewthread.php?tid=2465&a... ) is that Ti is self healing/ self sealing. Hopefully (that's hopefullly. It may not work) less demanding Lead Dixode plating conditions will produce workable, repeatable anode(s), it may not. Your opinion is that they will not work (the Ti substrate ones). I intend to try.

Quote:

Quote: Originally posted by Rosco Bodine Why don't you go buy yourself a pound of platinum instead of staying at me for a pound of flesh , Quote: Originally posted by Rosco Bodine because in the world of technology I am an apex predator . .............or have I just been ravished by a dead sheep! Dann2 P.S. Please disregard all insults towards Simon or/and Garfunkle.

@ DerAlte

This is true SCIENCE MADNESS...

Personally speaking, I am finding this quite an interesting endeavour, and thoroughly enjoying myself.

Here in NZ I have to import genuine graphite anodes from the US, the postage, etc, etc costs 5 times the price of the graphite. Gouging rods work, but they disintegrate fairly quickley, and introduce all sorts of colloidal contaminants.

The dream of going directly from salt to perchlorate with a perfectly clear solution, and anodes that only need replacing say once per year is highly desirable. After experiencing the simplistic beauty of a perchlorate cell using a platinised Ti anode and Ti cathode, there is no going back (well, with the exception of my 10 litre bucket cell, that is) for me!

DerAlte, I touched on this in an earlier post (and someone please correct me if I am wrong) but industry does not particularly need a anode (even a fairly efficient one) that goes from salt to perchlorate. They have ultra efficient - long lived chlorate anodes, and the same for perchlorate. The chlor-alkali industry is huge, the perchlorate small, they can use cheap chlorate for feedstock.

It seems to me that there is a lot of scope here for the amateur to try all sorts of things and even if a "holy grail" anode is half as efficient and has 1/10 the longevity of an industrial process it doesn't really matter.

Remember high temperature superconductors - who would have thought that, mix a witches brew of oxides together and bake in an oven.

If it proves possible to develop an anode that can be made simply, by baking a few coats of easily obtained materials on to it, why would any one want to go back to gouging rods or even graphite!

If we were to follow your line of reasoning we would still be listening to the radio using a cat's whisker and a galena crystal, it works, but not particulary well....
Oh, I thought of another, people were using candles to make light for centuries and they thought it was a really great way, until along came the incandescent, then the fluorescent and now the white LED. I know which process I prefer when trying to drill a hole in titanium, and it isn't a candle!

[Edited on 17-12-2007 by Xenoid]

[Edited on 17-12-2007 by Xenoid]

[Edited on 17-12-2007 by Xenoid]

@Der Alt-I have read your post before making perchlorate via carbon. If thats working to your satisfaction then great. This August/September was my first time making chlorate electrolytically. As much as I derived satifaction from it, I could not stand all the gunk and debris. I managed to obtain pure white chlorate after performing a number of filtering and purification parlor tricks but knew there was something better so I quit temporarily with my 700 or 800 grams of sodium chlorate. I feel Xenoid is on the same boat with me by hating the ridiculous crud. He is nothing less than inspiring especially considering Rosco's knowledge and perspective. Strangely, Roso spends so much time bashing dann2 yet I cannot remember seeing any actual working anode from him. It is not easy to experiment when one has so many obligations but I digress, some just talk alot.

@Xenoid-well got the heat gun now just need to prepare the precursor cobalt nitrate, nicke nitrate, and manganese nitrate. I have some bismuth metal if I can find it. Would like to make some bismuth nitrate soup So how is Gerty doing? Do you still have some lithium perchorate thing running?

[Edited on 12/17/2007 by chloric1]

[Edited on 12/17/2007 by chloric1]

Quote:

Originally posted by chloric1 @Xenoid-well got the heat gun now just need to prepare the precursor cobalt nitrate, nicke nitrate, and manganese nitrate. I have some bismuth metal if I can find it. Would like to make some bismuth nitrate soup So how is Gerty doing? Do you still have some lithium perchorate thing running?

Chloric - I have had to take a break (at the risk of divorce).

1) The 4-coat Co-spinel anode has finally passivated after 11 days in a chlorate cell.

2) Li (per)chlorate cell is still bubbling away, I added some more water this morning. I don't have a clue what it's doing or how long it will last!

3) "Gerty" is sitting on a bench, still awaiting a perchlorate catalytic outer coating! I plan to add several coats of Sb doped beta MnO2. I am about to make, hopefully some Sb nitrate (dissolve Sb2O3 in excess cold, conc. nitric acid).

4) I have obtained some iso-propyl alcohol to improve coating technique.

5) I have made some Pb nitrate which is crystallising at the moment.

6) I have sourced some 99.99% Bismuth here in NZ. I first checked Bi shot at sports shops, minimum purchase was 3Kg for a couple of hundred $$$s..
I have now found some for about NZ$40 per Kg but the company has closed down for Christmas and will not open again until January 7th... (Hey, this is NZ).

7) I am making another Chlorate cell using two of my MMO (RuO2/TiO2) chlorinator cell electrodes just to try them out!

8) I am stll not divorced...

Amen- Can't live without my wife and 2 year old but experiementing is definately frowned on here. I need to sell some of my anodes just to keep things in check. Told her I would use the heat gun to remove the death gray ugly paint off the kitchen cabinets. Need to buy the scraper though. I did prove to her how useful this gun is. Yesterday, the back gate lock was encased in ice and not only did I defrost it but heated bone dry! The relentess snow and ice has hampered my efforts immensely. I forgot my barium nitrate on my bench and it is covered in 12 centimeters of snow. It might be 2 degrees Celsius tommorrow. That is when I will reclaim my barium and at least react some cobalt sulfate with baking soda to get the carbonate. If I have enough beakers available I will try some soda with some nickel sulfate. I will be about 15% where I need to be but at least it is a start. I like summer better for comfort but winter is nice because the air is cold and dry. Great for crystalizing things!

Hello,

@DerAlt
Thanks for the compliment.
You have "given up reading Rosco’s verbose and repetitive posts"
I presume you are still reading my verbose and repetitive posts, eh

Regarding the Perchlorate with Graphite. I am a 100% 'doubting Thomas' when I hear of Perchlorate made with Graphite. Did you ever try a conc. sulphuric acid test on a 50/50 mixture of your Perk. + sugar. Use eye protection. Perhaps I asked you this before.
There are lots of accounts on the net showing great yields of Perchlorate from Graphite. The vast majority of them all stem from the one source 8/9 years written by a guy who has since admitted it was bullshit. I have not been able to make it in any sensible fashion or yield with C.
Roscoe posted a patent some time ago showing a cell with C and a diaphram. It would be a very interesting project IMHO.
http://www.sciencemadness.org/talk/viewthread.php?tid=8592&a...

Since this is a Co Oxide thread...................
My Co Oxide anodes are still going OK. Only two days so they have only started.
The DTO in Lithium Cell still OK, need to check for Perk. I need to see if the Perk. is forming yet (easily) as per the patent.

The DTO in Na Perk. cell has run now for 14? days. 'Run Time' of cell is 10 days.
I want to titrate the Chlorate to see if DTO can reduce the Chlorate level down to where it is sensible to simply take the liquid from cell and destroy all residual Chlorate to get pure Perk.

@Roscoe Perhaps a wee bit of indulgence was engaged in but I have to confess I did enjoy it!!!


Dann2
Totally, absolutely and completely relaxed communication with his fellow communicators in the Co Oxide thread.

http://i168.photobucket.com/albums/u200/anodes_2007/smash2vu...

p.s. Though shalt not speak ill of the Diamond Shamrock patents.

[Edited on 18-12-2007 by dann2]

Bismuth Oxide catalytic anode coating

@ Rosco, I will have to try Sb for the moment and even that is proving difficult. I wont have any Bi till the new year!

Regarding the 4 - coat Co spinel anode chlorate cell. It appears to have produced a considerable amount of chlorate. I put a few mls of solution in a test tube and added a little saturated KCl, there was immediate fine crystalline precipitation. I put it in the fridge and the solution is now about half crystals...

I've also checked this for perchlorate, but as might be expected it is absent!

[Edited on 18-12-2007 by Xenoid]

Quote:

Originally posted by Xenoid @ Rosco, I will have to try Sb for the moment and even that is proving difficult. I wont have any Bi till the new year! Regarding the 4 - coat Co spinel anode chlorate cell. It appears to have produced a considerable amount of chlorate. I put a few mls of solution in a test tube and added a little saturated KCl, there was immediate fine crystalline precipitation. I put it in the fridge and the solution is now about half crystals...

@Xenoid , that's a good deal , it's snowing chlorate
The Co spinel has useful properties in at least three different schemes , which happen to be the same three schemes that are being applied here , and that's no coincidence , it's an integrated system being conteplated .
It's when the three schemes converge that longevity
and efficiency should result . Up to this point your experiments are really preliminary tests which reveal promise for the larger scheme working . So far so good .

A quick OTC source for Bi may be fishing sinkers , egg sinkers up to 3/4 ounce are in some stores . I still have to get some Mn and do the improvised method on that for
nitrate . Regarding the Sb , antimony can actually have some catalytic effect alone and can also act as a dopant on the bismuth , but my educated guess is it is likely the bismuth that will be the principal active catalyst component in the outer coating , but the Sb will be a good
included component in the system for other reasons.

And Bi is known to work with lead , US4101390 shows
87% curent efficiency for chlorate and also claims good perchlorate efficiency with very small catalytic amounts of Bi added to PbO2 . I believe it is a parallel with the baked MnO2 anode of US4072586 ,
only the method of dispersion would be different for the
baked MnO2 anode . That was why the 50nm Bi2O3
gotten on reflux overnight at 100C caught my notice .
I am not sure about the thermal properties , so a different method may be required , but it may be possible just to add the Bi2O3 nanocrystalline material as a thixotropic
component to your final baked coating , and bingo you
should have a catalytic anode coating with high selectivity for chlorate / and perchlorate . Hopefully 90% current efficiency can be achieved on the perchlorate from chlorate , and it should be correspondingly good for
the other stages up from the chloride as well .

There still needs to be an SnO2 sealing layer over the spinel interface . I am positive on that . But the sealing
SnO2 over spinel should be a no fuss SnO2 since it
is only a sealing layer and not some multipurpose
coating having to be handled some special way ,
as when the interface has not been already resolved .

Even if the Bi-Pb electrodeposition ended up being the
outer coating , that coating is very thin and should not
be any laborious plating .

What the idea is with this sandwich layering is to
put the best materials to work at what they do best ,
instead of trying to make one coating that can't do it all
be multi-tasked to destruction trying to do the impossible .

The layer system system I have been contemplating
works as follows :

The hydrided substrate is stable up to ~200C .

The spinel is a superb interface and anti-passivation
material which takes the handoff on baking from the hydride , and anti-passivates the Ti creating a stable though not yet perfectly encapsulated substrate .

SnO2 hermetically seals that spinel coated substrate .

And then the working anode coating complete with catalysts goes on the outside .

If that is a repetition of what I said before , sorry
I lost track . I am going to request some references
to better pin down the final details on how to use
the Bi in the baked coating scheme . I'll get back
with those references later .

Edit: See attached article
Synthesis of bismuth oxide nanoparticles at 100 -C

[Edited on 18-12-2007 by Rosco Bodine]

Attachment: Synthesis of bismuth oxide nanoparticles at 100 -C j.matlet.2005.03.037.pdf (116kB)
This file has been downloaded 8820 times

I am open to any suggestions or theories as to the mechanisms or the various proposed schemes for getting the Bi into the baked coating .
There is going to be diffusion on baking among whatever form precursors are used , not only within the outside layer
but between the layers . It is something like the way an automobile tire is made from layers that are then heated
and fused together into a unitary structure having embedded
components , with the Bi here will be like "snow studs" and
perhaps some of the "tread" layer , where the rubber meets the road . The "snow studs" in this analogy would be distinct 50nm microcrystals , like a speckled egg or sand in
wet paint , a separate phase , but having those particles
diffusion bonded into the composite , like tiny icebergs in a frozen sea .

I have some imaginings what it might look like if you could
climb into a tiny nanospacecraft and descend to take a look
http://www.youtube.com/watch?v=wpLNsdbOPPs&feature=relat...

Heck I trust Xenoids results already , and no real surprises there except it works even better than expected
So I want to look at the 7:3 cobalt-nickel spinel interface
but by the time I get around to it , it will already be done
probably by Twospoons , IIRC . I can't help the delays ,
as I have a plateful of other stuff that keeps me at a
distance , and this is like the model airplane that goes
together a piece at a time , over many months where I
can take a few minutes here and there , to apply to the build . You fellows are three months ahead of me on implementation , but I have also been scrounging the references as well as the hardware . If this works out , maybe patent the anode and let the proceeds act as a trust for this forum , to keep the site going in perpetuity . In a way it is already public domain , but in another way it is ultimately Polverones , for indulging us in such pursuits . Call it a work for hire where we worked for peanuts , if it doesn't turn out to be just another back to the drawing board scenario .
Given the sad state of affairs for science in the schools ,
this waterhole needs to kept a well in the desert long after we are all gone as a legacy .


[Edited on 18-12-2007 by Rosco Bodine]

Yeah this forum is a quite unique and a valuable resource
for brainstorming , an informal think tank of sorts ,
some small comforting sanctuary for thinkers and experimenters .

My reference mining for bits of useful information is not really producing any significant search hits anymore
and I am getting crosseyed from reading the more general
long lists of hundreds of more vague sorts of search results trying to find anything more . So it is probably time
for me to close the search for more unless some new parameter for possible search hits occurs to me .

The spinel I think really is the most promising interface
because the conditions required for getting it right are
fairly easily reachable , moreso than alternatives .

The sealing layer of SnO2 also is simplified .

The outer coating and getting the selectivity for good
efficiency for a perchlorate anode is where the technical difficulty arises , because the "recipe" for that *special*
baked coating is not well specified . So here comes the experiments , and reverse engineering by guess and test .

However , the Bi + PbO2 electrodeposited perchlorate
anode coating is well detailed and is one of the thinnest platings that is advertised to work well and have good
service life . No guessing there .

So there really is no good reason to get overly discouraged about the uncertainties concerning the outer layer where a baked coating there is desirable ,
because even if a very good one is never found ,
there is still the old standby electrodeposited coating which should work , and being a thin layer deposit
could be just fine .

IMO , either way it goes with the wearing coating ,
the overall system is still more easily implemented
and more likely to work well for a long time , than
alternative schemes . Anyway ...it's different

Now , I think I'll take a break , need some downtime .

Gertrude the Anode

Hello,

Some of the articles for DTO going onto Ti have heated the Ti up to 480C or so (decomposition temp. of the Tin Chlorides) and then sprayed on the DT0 precursor. Might work for the Mn if you put the precursor in a perfume bottle (the one's you can refill) and spray onto hot anode to stop the problem of the precursor not wetting the anode. It will dry instantly.
You could mix precursor half and half with perfume to keep Gertude sweet too

My two Cobalt Oxide anodes that I was testing in Chlorate cells failed some days ago. The one with the ligher coating failed one day, approx. before the one with the heavier coat.

Dann2

[Edited on 23-12-2007 by dann2]

We know what reportedly wets anything including teflon
is the mixed valency tin chlorides polymer of US3890429 . Situations like this would seem like a good place to put it to use .

Other good anode names are of course Lola and Bertha ,
Dolly and Mabel and Elvira


[Edited on 23-12-2007 by Rosco Bodine]

Quote:

Originally posted by dann2 You could mix precursor half and half with perfume to keep Gertude sweet too {quote] Dann you are a card! But no seriously, I feel your observation is quite sensible if you cannot get good wetting. After all, when Gerty was first made, the Ti rod was etched providing a workable surface for the first coatings. And the manganese just morphed into the cobalt oxide coating. @Xenoid- I was sure that Gerty was going to be a good performer. If not a good perchlorate maker at least a decent MMO for long term chlorate making use. It seems that the manganese might not be stable enough on its own. Or maybe you should start with NaCl brine and try all the way to perchlorate. Personally, I don't understand why you are getting manganese leached into your solution unless the manganese was not completely decomposed. Maybe a longer bake time might help. @Rosco-IMHO these silly names might actually have scientific value in these quest or ours. These would serve as simple identifiers to anodes made by specific methodologies in a certain sequence. Provided an accurate and complete discription is available from the start the contents and properties of said anode would be understood in the forum when me, you, Xenoid, or someone else says Bertha gave up the ghost in 5 days in brine. I have a four day weekend and am hoping to turn out at least one anode. The name I am considering is Dorothy. [Edited on 12/23/2007 by chloric1] [Edited on 12/23/2007 by chloric1]

Update on Gertrude: After 20 hours, electrical parameters are stable, the slight rosy pink ??Mn(II) colour has faded, I think it may have oxidised to MnO2 as there is a little black on the bottom of the cell, black MnO2 from the meniscus has largely disappeared as well!
I will check for perchlorate at at 24 hours, and also increase the current density to 50mA/cm^2.

Re Naming: Lets not be sexist about this. I am about to clone Gertrude in a male form (Hubert). Hubert will be placed in a chlorate cell and tested to destruction...

Also the anode description protocol used by R.P.Wang is usefull, list the anode components outwards, perhaps adding a number for the number of coats. In this system, Gertrude would be:

Ti/2xCo3O4/14xbetaMnO2

[Edited on 23-12-2007 by Xenoid]

You're working with rods, right? A male name would generally make more sense then. Freud would agree.

Tim

Uhhhh ...... Tim , it's not the rod itself that is the primary interest here , but rather the processes and most satisying
coatings applied thereon , you know , what sort ,
how many times ...how hot , .......the benefits of threesomes in coating sequences , endurance , and so forth You just need to broaden your perspective .

Ah, true...

Gertrude makes perchlorate.

Update on Gertrude and her adventures in a perchlorate cell.

Well to cut a long story short, I completely messed up the testing procedure!

1) I carried out the testing with what I thought was saturated NaClO3 solution, but after carrying out some density measurements (1.22) it was actually only 354g/L or only ~ 106g NaClO3 in my 300 ml test cell.

2) About 1/3 the way through the run, I decided there was "something wrong" with the solution, I thought perhaps it was NaCl. I won't go into my reasons for this, but suffice to say I changed the electrolyte. As it turned out, to exactly the same concentration and composition.

3) I varied the current density 3 times, starting at about 25 mA/cm^2, increasing to 50 mA/cm^2 and finally increasing again to 75 mA/cm^2. These were carried out at approximately 24 hour intervals.

4) My initial fears about "Gerty" not producing perchlorate were totally unfounded. She has produced copious quantities, there was a problem with the methylene blue test (see below). If doping with Bi improves perchlorate production that will be even better.

5) I added two "lots" of unweighed solid NaClO3 crystals, during the testing, so the true amount present is any bodies guess!

Basically Gertude has run for the equivalent of 76 Amp hours in a low NaClO3 concentration perchlorate cell (see attached image) at the above mentioned current densities. Unfortunately she has not come through unscathed, although still appearing "as new". The presence of purple permanganate, and black precipitate indicates the anode has eroded, how much, I'm not sure. Much of the detritus in the cell has turned out to be erosion products from the SS cathode (especially from the head space area). As I pointed out elsewhere, if you want a clean running cell (chlorate or perchlorate) use Ti cathodes.

Methylene Blue (MB) testing:

When running previous Pt based perchlorate cells I have never had a problem with this test, an intense violet ppt. is formed. This holds true for the Li perchlorate cell I am currently running, as well.
With this "Gertrude" based cell, however, my first 3 or so checks produced negative results. Finally in desperation I added a few grains of NaOH to ensure the solution was alkaline, before adding the MB, this resulted in an immediate violet ppt. I was confused by this because Dann2's pages mention perchlorate cells drifting alkaline. I then attempted to check the pH of the cell. I don't have a pH meter (I have now ordered one) so I used some fish tank indicator. I think this is bromophenol blue in a pH=6 buffer solution as it is a yellow colour. When added to the electrolyte the indicator went a bluish green then in a few seconds turned yellow indicating a pH around 5 - 6. Thinking this was a little strange, and that there was perhaps some bleaching action, I boiled the solution but this made no difference. A check with the indicator in the Li perchlorate electrolyte gave an instant pH ~= 5 indication. Subsequent tests showed MB gave positive results for K perchlorate in a solution acidified with 5% H2SO4. MB gives negative reaction to weak permanganate solution.
A diluted solution of electrolyte from the "Gertrude" cell gave a yoghurt ppt. with saturated KCl.

So a couple of questions:

1) Why are both the "Gerty" electrode cell and the Li perchlorate cell drifting acid instead of alkaline?

2) Why the unusual reaction to the indicator, by the "Gerty" cell?

3) Why a negative result for MB in an acid solution for the "Gerty" cell when MB clearly works down to at least pH = 4

I have now restarted "Gertrude" at 1 amp (50mA/cm^2) and 4.0 volts in a fresh NaClO3 cell of density = 1.39, this corresponds to a 46% solution (near saturated) and 192g in my 300 ml cell.
At 100% efficiency 96.8 amp hours are required to convert this to perchlorate.
At 50% efficiency 193.6 amp hours are required to convert this to perchlorate.

Sorry for the long post, but I was typing it up for my own notes.

Edit: Whoops! The blue pen mark next to the anode indicates the approximate electrolyte level. There is no obvious erosion line on the anode!

[Edited on 26-12-2007 by Xenoid]

Methylene Blue and pH Drift

Hello,

Some info I have on MB testing enclosed.
It mentions Nitrate 'interference' in the stuff out of the 'Perchlorates' (book) but I do not know exactly what they mean.

The presentation is very nice>>>>>>.

Dann2

[Edited on 27-12-2007 by dann2]

Combined coating / sealing strategy

Earlier in response to chloric1 I mentioned that some of the elements of what seems to be a complex coating scheme
might be integrated in some way to simplify things . So here
is an idea which may work fine in that regard .

There remains in my estimation a usefulness , possibly even a necessity for the SnO2 component being involved in these
layered coatings , only I believe it can be better implemented
in other ways than by use of the strictly SnCl4 or Sn+IV alcoholate(alkoxide) based schemes .
The Pytlewski patent US3890429 describes the mixed valency polymer forms of colloidal SnO2 which may be formed as higher precursors for the desired SnO2 baked coating , even though the patent does not specifiy this end use . Clearly the chemistry of these inorganic polymer forms of SnO2 *spotlight* such materials as being of *great interest* as precursors for baked coating schemes , because of their structure and properties , including being capable of being doped at a molecular level with other selected metals of particular interest , like Sb , Co , Ni , and Bi . The ability of the polymer
to form a dried , persistent and highly adherent film of
1000 Angstroms thickness , even *without baking* , a film having a *profound* hydrophilic character , yet will not simply wash off the surface , but which acts as a residual
"wetter-sticker" for causing other aqueous systems to
sheet evenly across the surface , is a remarkable property .
Further , the chemical composition of the inorganic polymer
is such that upon being subjected to baking temperatures ,
it fully dehydrates and forms the desired doped tin oxide ,
with its doping either derived from included dopants introduced in its molecular structure in advance , and/or
securing its doping by diffusion from adjacent coatings ,
below , above , or both .

It would therefore seem possible to form the Co3O4 spinel
interface concurrently with a DTO sealing effect , and perhaps to enhance the quality of that spinel layer , by
using the SnO2 inorganic polymer as a wetting agent .
The SnO2 polymer could be applied directly to the freshly hydrided Ti , and simply dried , and then the Co(NO3)2
applied and baked . Each subsequent coating of spinel
could be preceded by a dipped and simply dried on film
of the polymer wetting agent . It would serve to even the wetting out for the Co spinel precursor , and then fuse
together with it on baking , sealing and bonding the grain structure .

Alternately , the initial cobalt spinel interface coating
could be applied as already proven , and the SnO2 polymer
used as a "dip and dry" treatment ahead of the second
and every other subsequent baked coat of spinel . It should work either way . And the wetting out ability of the SnO2 polymer should be especially useful as a remedy for the
wetability problems which arise later with the MnO2 .

Not a half bad idea huh ? It works on paper anyway

[Edited on 28-12-2007 by Rosco Bodine]

Making Hubert

Hubert is Gertrudes big half-brother!

Surface preparation and etching:
The Ti rod was run in a drill press, and sanded with 80 grit garnet paper for 1 min. and then 100 grit paper for 1 min.
The rod was then etched in hot concentrated (290 g/L) hydrochloric acid for about 10 mins. I do this by placing the rod in a test tube containing just enough (about 1/2 full) HCl that the level rises to the top of the tube. The tube is placed in an empty 400 ml beaker on a hot plate. Eventually H2 bubbles will be evolved from the shiny Ti surface and it will turn dark grey. The HCl will turn pale violet or mauve. The rod is then well rinsed with distilled water.

Co3O4 (spinel) interface coating:
A test tube was about 1/2 filled with an ~ 50% solution of cobalt nitrate hexahydrate. This was made by dissolving 20g of moist crystals in 20 mls of water. This solution is dark red. The etched portion of the rod was dipped in the solution for 15 secs. and wiped against the inside of the tube as it was slowly withdrawn. The drop of liquid usually adhering to the end of the rod was absorbed on a piece of paper towel. The rod was hung in the previously described heat gun arrangement(see page 3. of this thread), and the heat turned up to 380 oC +/- 10 oC. The heat was maintained for 10 mins. (Use an egg timer or similar!). The heat setting was then turned to minimum and the hot air cooled down to about 50 - 60 oC. At this point the gun was turned off and the rod allowed to cool further for a few mins. The rod was then removed by its wire hanger (careful it's still very hot) and wiped lightly with a soft cotton cloth to remove any loose material or "crusty" build-up. Mark off one coat with a tick on a piece of paper (don't forget this, it's very easy to lose track). The rod is then cooled to room temperature by walking around waving it. In the case of Hubert this dip 'n bake procedure was repeated 3 times more, for a total of 4 coats.

Beta-MnO2 over coating:
A test tube was about 1/2 filled with a 1.2 M solution of Mn(NO3)2 which had been stabilised with a few drops of nitric acid. The solution is a pale pink-rose colour. The rod was dipped in this solution and baked in exactly the same manner as outlined above. This coating procedure was repeated 10 times. After the last coat had "baked" for the allotted 10 mins. the rod was baked for an additional 30 mins. at 380 oC. After this the rod was slowly cooled down over a period of 30 mins. by slowly decreasing the heat gun setting.

The main differences between Hubert and Gertrude are;
1) Co3O4 baked at 380 oC versus 370 oC
2) 4 coats of Co3O4 instead of 2
3) beta-MnO2 baked at much higher temperature of 380 oC
4) 10 contiguous coats of beta-MnO2
5) rod was annealed, by slowly lowering temperature at the end

Using the secret coding system known only to the Fraternity of Anode Fabricators;
Gertrude = Ti/2xCo3O4/14xbeta-MnO2
Hubert = Ti/4xCo3O4/10xbeta-MnO2

To obtain the higher temperatures used for Hubert, I placed tape over two of the air inlet slots on the heat gun.This slows down the air flow, and meant I could reliably achieve 400 oC.

This coating system is loosely based on US Patents; 4072586, 4265728, 4366042, and 4368110

The image shows Hubert with the simple wire jig used for hanging him in the heat gun tube

@ Rosco
The main problem for me at the moment seems to be the slow degradation of the MnO2 coating. Gertrude has now been put in a new saturated perchlorate cell and seems to be behaving well electrically, but the MnO2 coating is breaking down physically. The cell is colourless, but there are specks of black ?MnO2 increasing all the time.
Perhaps Hubert will solve this, with his higher temperature baking, time will tell ..

You should try what I am suggesting for the SnO2 if
you have the materials available . I have plenty SnCl4
and SnCl2 and Sb2O3 , but no Mn nor Bi compounds .
( still collecting components )

I did a pretty extensive survey of the literature ,
and it seems I am getting resistance to "off label use" suggestions ( which is *exactly* my forte ) .
When old Rosco spots a potential off label use for
something , he has a pretty good record for being right .

I see what you are running into there and I am trying to
tell you what might fix it . You mentioned using an agricultural
wetting agent and this is the same idea , only using something better suited for the task . The film produced
is however very thin , and a more substantial amount of SnO2 will probably need to be used also to accomplish the sealing to a maximized extent . It will depend on how loaded
with solids the mixed valency sol can remain stable on evaporation and concentration whether it can suffice alone
as the precursor for SnO2 . The nitrates also form the Pytlewski polymers . The anomalous case of tin nitrate combined with iron , aluminum , or chromium nitrate to form a highly concentrable "hydrogel" as was described in that hundred year old reference which I attached earlier , is very likely a nitrate based Pytlewski polymer which would work in this scheme as it is a highly concentrated mixture .

If a different polymer mixture does not form a stable , highly loaded dispersion , then another sol or ammonium stannate or some other SnO2 precursor may be required also . This might mix with the polymer or be applied separately as a second dip .

Probably the technically simplest approach to adding thickness for the SnO2 layer , after an initial coating with the polymer wetting agent , is simply to use the oxidative cold soak deposition of SnO2 from a SnCl2 + NaNO3 solution .
It is slow but sure .

BTW , I have some nickel carbonate now to go with my cobalt carbonate ....and have some type K thermocouples
on the way . Still need a heat gun , been looking at
the Makita thermocouple gun .

Some of the lead free solders that aren't the 95/5 Sn/Sb
but are silver bearing , may also have some Bi , a few percent .

Putting some MnCl2 or Mn(NO3)2 into the electrolyte
as a deliberate contaminant , additive might help protect the anode via common ion effect . Also using a bit of carbonate 5-10% along with the nitrate and baking
a bit hotter like you are doing could help . Also
using ~5% of the Co nitrate along with the Mn nitrate
could help , with or without the carbonates . But I think
the inclusion of SnO2 will do a lot more good .

[Edited on 28-12-2007 by Rosco Bodine]

Well, I am open to SnO2 polymer sols. I was hesitant at first since they seem a little fickle compared to cobalt spinels. At least until you posted a patent on mix valency tin with PVA. That immediately caught my interest as I imagined an organic matrix supporting the inorganic oxide. I know the PVA will not survive the heat but what a cool wetting agent I just might order some soon since I have not played with it since highschool 17 years ago! I have also read about PVA as a binder for cermics prior to firing but which ones I don't know.

That was a mixed ammonium stannate / ammonium antimonate composition rather than a mixed valency polymer sort of composition which used the PVA thickener . You are talking about US6777477 , right ?

However that patent did show the production of a precursor which is also of interest in other ways ,
such as for the making of tin(IV) nitrate . When
the tin(IV) chloride is neutralized with ammonia ,
the precipitate is the desired hydrated stannic oxide ,
which does neutralize nitric acid completely . The
tin nitrate solution formed is unstable above ~50C ,
(by itself) but when it is combined with certain other
metal nitrates , at the proper pH , it forms a stable
hydrogel which has a high metals loading and needs
no PVA thickener .

This is the direction I think is most promising of all ,
as it would likely give the same good nitrate derived baked coatings for SnO2 and doped SnO2 , as has been
showing good results in Xenoids experiments for the nitrates of Co and Mn .

The oxidative soak deposition of SnO2 from SnCl2 + NaNO3 also seems to be good bet as the simplest way
of applying an SnO2 layer , if one has the patience to
wait for the hours it takes to slowly deposit . That
method could be the reaction left overnight to slowly
deposit .

[Edited on 28-12-2007 by Rosco Bodine]

Yeh I think that was the right patent. Sorry I got my wires crossed yesterday, its easy to get confused with a fever of 38°C.
I have prepared solutions of cobalt and nickel nitrate. I was going to refer to the approximate mass of elemental metal dissolved in a designated volume of water. Unfortunately, when dissolving my nickel sulfate in water,with haste, to make nickel nitrate I forgot to measure how much I used. I still have to make some manganese nitrate. Judging from the patents, it seems probable that it would be OK to bake at 400°C and for a little longer times.

Chicken soup and pseudoephedrine and paracetamol and orange juice for you . Soak in a hot tub until you break a sweat ....sometimes that will help too . I'm a little under the weather myself . Bears should be hibernating this time of year

If you have good analytical scales , a quadruple beam Ohaus 311 centigram for example is okay ....
You can always take a sample of your unknown solution ,
( analysis of an aliquot compensates for a sore twat )
And then you do your quanitative analysis based on
precipitation of the carbonate for example . In this
case save the analysis sample of carbonate because it reportedly improves the nitrate bakeout to include about 10% of the carbonate in the nitrate coating mixture , for manganese this is reported to be true anyway . It probably follows for the other nitrates as well , where
the carbonate likely serves to thicken the mixture and/or
buffer and smooth the decomposition on baking .

I have some tangential references which mention tin nitrate related information and I will post them in dann2's
thread regarding antimony and tin nitrate .
http://www.sciencemadness.org/talk/viewthread.php?tid=8347

[Edited on 29-12-2007 by Rosco Bodine]

++++ Gertrude is Dead ++++

Long live Hubert...

I am sorry to report that the brave little anode Gertrude (known affectionatly as "Gerty" to some of you) died this afternoon local time.

During her short lifetime of approximately 146 Amp hours, in the often harsh environments of assorted perchlorate cells, Gerty is estimated to have converted about 280g of NaClO3 to 322g of NaClO4.

Gerty died from the hideous effects of slow passivation followed by massive overvoltage application.

Please do not let this happen to your anodes!

Gerty died alone, while I was having a pleasant hike in the mountains. I had inadvertantly left the voltage limiting set to maximum (~ 30 volts) on my lab power supply while running in constant current mode (1 amp). I am not sure what the exact "breakdown" voltage for the passivated layer is, but it obviously less than 30 volts...

I now have a 300 ml perchlorate cell "chocka-block" full of steaming, white, TiO2 gloop!

Moral, never apply more than about 10 volts across a Ti anode in a perchlorate cell!

I have more "bad news" but I am too distraught to report it at the present time...

[Edited on 29-12-2007 by Xenoid]

Noooo!

Look at it this way: clean 'er off with some acid (or sandpaper, or...), recoat and you'll have more surface area!

Tim

Gone too soon , we shall miss Gerty ......

The flower of youth is fleeting , it lasts but a moment .
She looks so ....unspeakably horribly ravaged
You can almost hear her crying out in final despair
"goodbye cruel world"

RIP Gerty , a musical tribute and farewell
http://youtube.com/watch?v=oiFTXckh0zU&feature=related

Quote:

Originally posted by Xenoid Long live Hubert... I am sorry to report that the brave little anode Gertrude (known affectionatly as "Gerty" to some of you) died this afternoon local time.

Quote:

During her short lifetime of approximately 146 Amp hours, in the often harsh environments of assorted perchlorate cells, Gerty is estimated to have converted about 280g of NaClO3 to 322g of NaClO4. Gerty died from the hideous effects of slow passivation followed by massive overvoltage application. Please do not let this happen to your anodes! Gerty died alone, while I was having a pleasant hike in the mountains. I had inadvertantly left the voltage limiting set to maximum (~ 30 volts) on my lab power supply while running in constant current mode (1 amp). I am not sure what the exact "breakdown" voltage for the passivated layer is, but it obviously less than 30 volts...

Evidence shows clearly that this was no accident but murder most foul . The usual suspects are believed to have been responsible . She was overpowered and forcibly
oxygenated again and again and again , until she was dead . The body was mutilated and crows are yet observed
picking pieces of her rotting remains from the trees . It is all so .....ghastly

Quote:

I now have a 300 ml perchlorate cell "chocka-block" full of steaming, white, TiO2 gloop! Moral, never apply more than about 10 volts across a Ti anode in a perchlorate cell! I have more "bad news" but I am too distraught to report it at the present time...

You mean it gets worse ??? Brace yourself and tell us ,
screw your courage to the sticking place ,
and let us hear it ....the rest of the story

[Edited on 30-12-2007 by Rosco Bodine]

@ 12AX7

Hmmm.. I think she's past the "cleaning up with sandpaper" stage. One thing I was thinking about though, is that if this process was carried out in a "more controlled" manner it might be possible to produce a high surface area that bonds well to any interface layers. Actually, I don't think sanding produces all that great a surface, it's more like lots of smooth grooves.

If the Ti was corroded using say 10 mA, or 100 mA, who knows, at the breakdown voltage, it might produce a superb bonding surface akin to sandblasting, but better. This could be further enhanced with HCl etching. One problem, is that the high voltage breakdown starts at defects and pinholes, and might not produce an even surface. A low current over a longer time might solve this though.

@ Rosco

Don't fret Rosco, my "bad news" has nothing to do with coating Ti anodes. It concerns "Big Bertha", my 10 litre, 12 gouging rod chlorate cell. It relates to the application of 25 amps through SS junctions in the presence of saline solution, chlorine and air. I can't believe I cocked this up twice in about a week...

@Xenoid-You said Gerty got ate up by a condition of overvoltage because you did not set your limit to a lower level. I know the voltage increased slighty with your first cobalt anode, but I am not sure at what rate Gerty increased in voltage. If you could ballpark some relative graph or something to see if this manganese thing is indeed a step forward. Also, figuring total hours of use between the two. I believe that you stated your initial cobalt anode was useless for perchlorate. Once more data is produced the more it will have to be consolidated and organized.

@Rosco-A tad melodramitic dont ya think?!
I did enjoy the video you linked to it went well with my toast and coffee this morning.

[Edited on 12/30/2007 by chloric1]

Well, part of the problem was I messed around with solutions and current settings for the first 76 hours. I would say that based on 1 amp at 50mA/cm^2 she started the run at 3.7 volts which rose to 4.0 volts at the end of the 76 hours.

I then put her in a new cell where she lasted for about 70 hours, she started at 4.0 volts and after 50 hours was at 4.8 volts, on the morning of her demise the voltage had risen to 5.5 volts. I should have shut her down then, and she would have lived to make perchlorate another day, but the black coat still looked intact and "I just wanted to see what would happen". Now I know...

The beta-MnO2 coat was definitely a step forward as far as perchlorate goes. The 12 coat Co3O4 anode only ran for about 25 hours, under similar conditions.
The straight 4 coat Co3O4 was good in a chlorate cell, I think it was 13 days, I haven't tried beta-MnO2 in chlorate yet!

There is probably an inherent benefit from the differing
oxygen overvoltage effect derived automatically when
alternating layers of different materials are used in sequence , for *two* paired layer cycles like A-B/A-B as a configuration , because even if you don't know which
of the materials A or B has the higher oxygen overvoltage ,
the barrier will still exist for that labrynth if B turns out to be the layer with the higher O2 overvoltage . It would
result in shedding of the outer layer B , but then the
correct ordering would be encountered and further erosion
would then be opposed .

So using different layers in alternating fashion makes good sense as a strategy , even if there is not good specific information about the differences between the O2 overvoltage for the different layer materials being used ....
but only if at least four layers are used to hedge the bet
for that unknown . In scientific terminology , that is known as covering ones ass

Hubert's Fate

The fate of Hubert has been decided! He is to spend his life in the confines of a KClO3 cell. Why POTASSIUM chlorate, I hear you say. Well, a number of reasons;

1) I have never run a KClO3 cell, not much point with only graphite and gouging rods for anodes. I am approaching this with an air of optimism though and expecting this cell will run perfectly "clean".
2) I wanted to try and make some totally Na free KClO3.
3) I already have two NaClO3 cells running.
4) Experience with "Gertrude" and earlier anodes, suggests a chlorate rather than a perchlorate cell is a safer place for an anode of Hubert's composition.

I put together a more or less practical cell specifically to accommodate Hubert (see attached image). It has a capacity of 800 mls and an annular SS cathode and was cobbled together from bits of previous cells. The internal connections for the SS cathode are covered in glue lined heatshrink and the SS screw electrical connection is coated in hot glue. Hopefully this will prevent headspace corrosion of the cathode which has been causing me a few problems lately.

The cell has been running for about 28 hours now at 2 amps and 3.6 volts (55 mA/cm^2). So far there is absolutely no black specks of MnO2 floating around, this has plagued earlier MnO2 anodes. The cell actually looks like a large jar of pink champagne. But it's not a tipple I would like to try. More like a cocktail from hell. I was surprised to see small, flakey crystals of KClO3 settling on the bottom only 12 hours after starting. I thought it would take longer, but I suppose KClO3 is near insoluble in near saturated KCl solution. Looking good now, but what it will be like in a couple of weeks time is anybody's guess!

This wire had a layer of Co cathodically electrodeposited onto it from Co acetate & vinegar solution. It seemed to form a relatively thick, even, highly adherent layer.

After that it was heated in a gas flame for about 5 minutes, during which time the color changed from grey to blue/black.

Unlike the previous anodically deposited films, this coating cannot be rubbed off, smudged, etc.

Hopefully I'll get to try it in NaCl solution later today.

[Edited on by jpsmith123]

Update on Hubert

Hubert has been running in the 800 ml KClO3 cell for 3 days now.

The solution is a pale pink from MnO4- but has not increased in colour from beyond the first 12 hours. I think an equilibrium has been achieved with the MnO2 on the anode. This may be some sort of "common ion effect" as mentioned by Rosco. The colour looks worse than what it is, due to the strong colouration ability of MnO4-, and is really a miniscule amout that can be cleared away with a few drops of H2O2.

Other than the pink colouration, the solution is crystal clear (literally). I have dropped in a magnetic stirrer bar to improve the efficiency and this brought about a "snow storm" of 5mm of KClO3 overnight. There is now about 10 mm of crystal "snow" accumulated on the bottom, and it's really blowing a blizzard in there.

I'm very pleased with Huberts performance "so far".

In the background of the attached image you can see my chlorinator anode cell, note the disgusting colour. This is mainly caused by corrosion of the cathode in the "headspace" area. Some of the black "dusty" material appears to be coming off the MMO anodes.... gulp! The "theoretical" runtime finished a few days ago, but I'm going to let it go a few more days!

The 'Alembic' anode way way back used the same system and he has stated that many hundreds of hours were obtained from the anode without any visable signs of wear.
The anode is a bit of bother to make though. Did I mention it's of holy grail status??


Finally got around to titrating the product from a Perchlorate cell which had the DTO anode running in it. 5 coat anode.
This cell had been run for much much more than the run time of the cell (going from Chlorate to Perchlorate).
The cell product contains 79% Chlorate.
You also get ignition when the product is mixed with sugar and a drop of Sulphuric applied.

DTO is a hopeless anode for Perchlorate making. It lasts quite a long time though, approx 450 hours as far as I can remember.

The pink Chlorate cell is a VERY confusing sight. I could make some politically incorrect jokes........... but I won't.
Keep it up.

Dann2

Hubert and Purple Haze

"Hubert" and "Purple Haze" seem to be getting on very well together. This cell has now been running for over 6 days with absolutely no change in the electrical parameters, still 2.0 amps at 3.5 volts. I switched it off this morning and when the bubbles cleared Hubert's shiny blackness could be readily observed. The cell is still crystal clear, other than the pink tint. The KClO3 crystals are now twice as deep as in the image shown previously, and there are clusters of crystals adhering to the outside of the annular cathode. The KClO3 is now interfering with the stirrer bar and the electrolyte circulation. I guess I should "harvest" the KClO3 and top up the cell with saturated KCl and just keep it running.

@ dann2 - Yes I thought of all those jokes as well....

Its just a one eyed, one horned flyin purple chlorate maker...

I am happy for you and for Hubert. In this gray and endless winter it is nice to see the colors of spring! I guess this anode is going to have a life of several hundred ours.

It appears that 50 to 60mA/cm2 is ideal for this kind of anode.

[Edited on 1/7/2008 by chloric1]

Might sound sloppy but I have 1/4" diameter rods(6.35mm) and I am going to heat with the airgun and mount the rod with a clamp on a ringstand so I can hold horizontal. I use a heat gun every day at work so I am used to waving it and distributing the heat. I won a thermocouple on ebay for my digital multimeter but it will not be here for some time. Will have to watch the process to see what going on. When my thermocouple probe gets here, I may use a vycor tube and just support the titanium with one hole stoppers.

[Edited on 1/7/2008 by chloric1]