Titanium Chemistry

[jpsmith123]

Hello,

 

I realize that this is an old thread, but this seems the best place to ask: Has anyone yet tried anything with the pyrochlore idea?

 

 

Regards,

jpsmith123

[WSM]

Hello,

I realize that this is an old thread, but this seems the best place to ask: Has anyone yet tried anything with the pyrochlore idea?

Regards,

jpsmith123

 

It's gone to the back burner for the time being (and nagging the conscience terribly, by the way). Would love to pursue it actively if time and circumstances would allow (We haven't given up).

 

WSM

[jpsmith123]

Thanks for the reply.

 

I recently acquired some bismuth nitrate and bismuth citrate, and I may finally get a chance soon to do a quick experiment or two. (I'm plagued by living in a rather small place, and the little bit of "work area" that I have is cluttered with machine tools, electronics, etc., and this has been a serious hindrance to progress).

 

Anyway, here's the idea: I have a long-standing hunch that bismuth oxide - if it can be deposited as an adherent layer, in a "suitable" crystalline form, over a "suitable" substrate - will make perchlorate.

 

Apparently it's possible to electrodeposit delta-phase bismuth oxide onto a substrate from a warm alkaline solution of bismuth nitrate, tartaric acid and potassium hydroxide. (See this paper).

 

So I wonder: What if a few-micron-thick layer of delta Bi2O3 was deposited over an off-the-shelf MMO anode, or even over platinum? (Who knows, platinum might make a good substrate for a layer of Bi2O3, as the oxide may act as a replaceable working layer that protects and preserves the platinum).

 

One thing I wanted to try is to see if delta Bi2O3 can be electrodeposited from a solution of bismuth citrate in ammonia.

 

I'm wondering, has anyone here done anything along this line?

[Mumbles]

Bismuth does some very interesting electrolytic things (see Joel Rosenthal from Univ. of Delaware). Is there any particular reason that you believe that the right form of bismuth oxide over the right substrate will be able to make perchlorate? I'm not arguing or disagreeing. Just curious what you've seen or done to make you think this.

[jpsmith123]

There were a few patents from the 80s, e.g., 4267025 and 4272354 involving Bi2O3 as part of an anode coating claimed to be able to make perchlorate. But for some reason none of these apparently became commercially useful.

 

Then just a few years ago bismuth was again named in another patent which claimed that bismuth-containing pyrochlores will make perchlorate.

 

Taking these patents at face value it seems there's something about bismuth that suggests usefulness in perchlorate production.

 

Based on all the reading I did regarding the relevant properties of PbO2, e.g., how the crystallinity of the electrodeposited material affects the electrocatalytic performance, I think it's possible that delta Bi2O3 with its high ionic conductivity might be a substitute for Beta PbO2 in a perchlorate cell.

 

 

Edit: Here is another paper concerning properties of electrodeposited delta-Bi2O3.

Edited August 12, 2014 by jpsmith123

[pex]

Give it a try

[Mumbles]

Keep us posted. I'm for one very interested.

 

 

...

 

One thing I wanted to try is to see if delta Bi2O3 can be electrodeposited from a solution of bismuth citrate in ammonia.

 

I'm wondering, has anyone here done anything along this line?

 

Worth a shot I suppose. From reading the paper, it sounds like the tartaric acid templates the bismuth oxide layer. Citrate may or may not work the same. I guess you never know until you try. One thing that strikes me is that in addition to being a templating agent, tartaric acid/KOH will form a buffer to help stabilize pH in acidic conditions. You wont get the same effect with citrate/citric acid can act as it's own buffer, but the use of ammonia (being a weak base) may counter act it. You may have more luck using a strong base like sodium or potassium hydroxide.

 

A stable pH is important for making lead dioxide anodes as well. When you electrodeposit PbO2 from lead nitrate solution, you're going to generate nitric acid. Most often I see this being neutralized with lead hydroxide to control the pH, and keep adding lead. In industry, this can be done in a continuous process. For us buffers, using a large excess of lead, or occasional pH correction would probably be easier from a batch production point of view.

[schroedinger]

Well there is an very easy plating bad for pbo2 consiting of lead nitrate and sulfamic acid.

During plating nitrous acid get formed, this can be eliminated by the use of sulfamic acid. This gives a really hard coating

[WSM]

Well there is an very easy plating bad for pbo2 consiting of lead nitrate and sulfamic acid.

During plating nitrous acid get formed, this can be eliminated by the use of sulfamic acid. This gives a really hard coating

 

Can you share the details of this process or the source material it's gotten from?

 

WSM

[WSM]

There were a few patents from the 80s, e.g., 4267025 and 4272354 involving Bi2O3 as part of an anode coating claimed to be able to make perchlorate. But for some reason none of these apparently became commercially useful.

Then just a few years ago bismuth was again named in another patent which claimed that bismuth-containing pyrochlores will make perchlorate.

Taking these patents at face value it seems there's something about bismuth that suggests usefulness in perchlorate production.

Based on all the reading I did regarding the relevant properties of PbO2, e.g., how the crystallinity of the electrodeposited material affects the electrocatalytic performance, I think it's possible that delta Bi2O3 with its high ionic conductivity might be a substitute for Beta PbO2 in a perchlorate cell.

Edit: Here is another paper concerning properties of electrodeposited delta-Bi2O3.

 

An interesting thought. As Mumbles asked, "Is there any particular reason that you believe that the right form of bismuth oxide over the right substrate will be able to make perchlorate?", and I'm wondering if it's just a hunch or do you have any data to support it?

 

From what I've taken from my reading and observations, there are certain similarities between electrodes capable of converting chlorate to perchlorate, and a couple that stand out are 1) electrical conductivity, and 2) high oxygen overpotential.

 

I don't know if a delta form bismuth (III) oxide will work for converting chlorate to perchlorate, but the pyrochlore of ruthenium/bismuth oxides (Ru₂Bi₂O₇) is reported to do so (and hence our interest in it). If I remember correctly, even the crystal structure is similar to lead dioxide (if that matters).

 

Do you have access to the complete articles you're referring to? If so could you PM it or them to me? I'd like to see the full described details. Thanks.

 

WSM

Edited September 2, 2014 by WSM

[WSM]

Bismuth does some very interesting electrolytic things (see Joel Rosenthal from Univ. of Delaware).

 

When Swede and I started our study of the bismuth/ruthenium pyrochlore electrode patent application, my curiosity lead me to make a proof of concept experiment.

 

I took some reagent grade Bi₂O₃ and HCl and formed a solution of BiCl₃, which I coated on an MMO anode I prepared. The MMO is from laserred and reported to be a ruthenium/iridium electrode. I intended to bake the electrode at 350^oC for 24 hours and see if some spots of pyrochlore will form on the surface.

 

My test would be to put the modified anode with a titanium cathode in a cell of NaClO₃ solution and run it to see if any perchlorate forms (as tested with methylene blue solution).

 

I haven't gotten over to my friend's home (who has a kiln large enough to fit the electrode) to bake it for the stated time, yet. I'm thinking it's about time that I did...

 

WSM

Edited September 3, 2014 by WSM

[jpsmith123]

I also had that exact same idea, i.e., to put a layer of Bi2O3 over an off-the-shelf MMO anode, followed by heat treatment, hoping that some of the Bi2O3 might go into solution with the other oxides. (I've seen patents where a thin layer of metal was electroplated onto a substrate, then oxidized, then a thin layer of another metal, the "dopant", was plated, then oxidized, then the cycle was repeated several times, and finally the piece was subjected to a long heat treatment whereby the oxide layers would supposedly form solid solutions or something like that).

 

Anyway there was a time a few years ago when Dann2 (over at sciencemadness) started experimenting with Bi2O3, and I made the same suggestion to him at that time, but IIRC he was obsessed with trying to put a Bi2O3-doped-SnO2 coating onto bare titanium, and he couldn't get it to work, as the titanium surface would always passivate for some unknown reason at some point during the paint and bake cycle. So Dann2 apparently got fed up with it and gave up on Bi2O3 altogether without trying any other approach.

[jpsmith123]

 

As Mumbles asked, "Is there any particular reason that you believe that the right form of bismuth oxide over the right substrate will be able to make perchlorate?", and I'm wondering if it's just a hunch or do you have any data to support it?

 

I would say it's mostly just a "hunch", i.e., speculation, but I don't feel bad about it, as everything accomplished so far in this field seems to have happened on a trial-and-error basis (after all, look at all the patents that are out there and you'll find they're all about "recipes" with little or no theory).

 

From what I've taken from my reading and observations, there are certain similarities between electrodes capable of converting chlorate to perchlorate, and a couple that stand out are 1) electrical conductivity, and 2) high oxygen overpotential.

 

I agree. The high conductivity, in addition to contributing to electrical efficiency, may play a role with regard to keeping the electric field confined to the "surface", thereby preventing pinholes and/or other imperfections from becoming a path of current leakage to underlying material and/or the substrate. And having a generally high oxygen overpotential seems intuitively desirable, but there seems to be one or more other factors that are critically important. Apparently some kind of poorly understood physicochemical surface property is involved.

For example it "seems" like MMO should make perchlorate (and in reading Beer's patents, apparently he thought so too, as it's mentioned in some of the examples). Yet it seems that MMO anodes can only make perchlorate in very tiny amounts. (Apparently perchlorate is treated as a nuisance contaminant in MMO chlorate cells).

Anyway not long ago I found an interesting paper on the internet somewhere and one of the things investigated in the study was: why is BDD such a ridiculously efficient maker of voluminous quantities of perchlorate, compared even to platinum, for example? And to try to answer that the authors studied what was happening at the surface and just outside the surface of the BDD, and just as I got to the point where they were describing what they found, and speculating - based on their observations - why some other materials, e.g., MMO, don't make perchlorate (very well at least)...my problematic laptop overheated and shut down, and I didn't save or bookmark that paper.

IIRC the gist of it was that in the case of MMO for example the perchlorate ion that formed somehow got trapped at the surface of the MMO and blocked some critical pathway...it might have killed OH radical production or something like that. (One of my problems is that I've looked at so many abstracts and papers that my head is spinning and don't remember the details). I have to try to find that paper again.

 

I don't know if a delta form bismuth (III) oxide will work for converting chlorate to perchlorate, but the pyrochlore of ruthenium/bismuth oxides (Ru₂Bi₂O₇) is reported to do so (and hence our interest in it). If I remember correctly, even the crystal structure is similar to lead dioxide (if that matters).

 

AFAIK the only source of information claiming that Ru2Bi2O7 pyrochlore will make perchlorate is one patent. I haven't seen any literature, e.g., peer reviewed papers, supporting it. It may work as claimed...but it may also have issues and end up like all the other patents by De Nora, "Diamond Shamrock", etc., that ay have seemed promising but never amounted to anything for some reason.

 

Do you have access to the complete articles you're referring to? If so could you PM it or them to me? I'd like to see the full described details. Thanks.

 

I have to look and see what I can find on this HD. (BTW if you need bismuth compounds, there are a few people selling bismuth nitrate pentahydrate fairly cheaply on ebay, and I found a relatively cheap source of bismuth citrate from a company called "Bio Basic".

[Mumbles]

If you guys can find any of these articles from peer reviewed journals, I might be able to help you out if they're behind a paywall.

[WSM]

If you guys can find any of these articles from peer reviewed journals, I might be able to help you out if they're behind a paywall.

 

The first link appears to be: http://www.researchgate.net/publication/243338452_Low-temperature_electrodeposition_of_the_high-temperature_cubic_polymorph_of_bismuth(III)_oxide and not having credentials as an academic prevents me from accessing the document.

 

The document you reference ("Bismuth does some very interesting electrolytic things (see Joel Rosenthal from Univ. of Delaware).") would be interesting to review, also.

 

Thanks, Mumbles!

 

WSM

Edited September 4, 2014 by WSM

[smokeytech]

has anyone tried these equations with other metals?

 

http://www.mypixshare.net/files/img/user_uploads/displayimage.php?id=gu2ib0ek4zk02379791.gif

[WSM]

 

When Swede and I started our study of the bismuth/ruthenium pyrochlore electrode patent application, my curiosity lead me to make a proof of concept experiment.

 

I took some reagent grade Bi₂O₃ and HCl and formed a solution of BiCl₃, which I coated on an MMO anode I prepared. The MMO is from laserred and reported to be a ruthenium/iridium electrode. I intended to bake the electrode at 350^oC for 24 hours and see if some spots of pyrochlore will form on the surface.

 

My test would be to put the modified anode with a titanium cathode in a cell of NaClO₃ solution and run it to see if any perchlorate forms (as tested with methylene blue solution).

 

I haven't gotten over to my friend's home (who has a kiln large enough to fit the electrode) to bake it for the stated time, yet. I'm thinking it's about time that I did...

 

WSM

 

 

I forgot that I had photographed the sample MMO electrode I coated with bismuth chloride:

 

 

It has been sitting since. I need to bake it at 350^oC for 24 hours according to the patent information. Then testing it in a cell with NaClO₃ will tell whether it produces perchlorate or not.

 

WSM

[jpsmith123]

I think the idea has serious merit, but BiCl3 may not be the precursor that you want to use. IIRC, somewhere I read that when BiCl3 is heated in air, some of it evaporates and some is converted to BiOCl, which is temperature stable to about 600 degrees C (or something like that).

 

I could be wrong about this, but the nitrate or citrate may be better choices for this experiment.

[WSM]

I think the idea has serious merit, but BiCl3 may not be the precursor that you want to use. IIRC, somewhere I read that when BiCl3 is heated in air, some of it evaporates and some is converted to BiOCl, which is temperature stable to about 600 degrees C (or something like that).

I could be wrong about this, but the nitrate or citrate may be better choices for this experiment.

 

When it evaporates, the chlorine leaves and bismuth oxide is left and our hope is that the oxide mixture (MMO and Bi₂O₃) melts and combines. The attempt was a proof of concept, to see if some spots of bismuth ruthenium pyrochlore appear on the surface and if they do, indeed produce perchlorates.

 

I believe ruthenium chloride is used in the process to make MMO in a similar fashion.

 

WSM

[jpsmith123]

 

When it evaporates, the chlorine leaves and bismuth oxide is left...

 

 

 

My concern is, at what temperature does this happen?

 

 

Edit:

I just checked my CRC Chemistry and Physics Handbook, and it shows a boiling point of 447 degrees C for BiCl3, so that may be why I can't find any examples of anyone thermally decomposing BiCl3 in air to make Bi2O3.

 

For some reason it's hard to find information about thermal decomposition of bismuth compounds in general. Here's a paper (abstract) claiming that bismuth citrate decomposes to alpha-Bi2O3 @ 360 degrees C, so that would seem to be a possible precursor for your experiment. I think the citrate will dissolve in ammonium hydroxide, but I don't know how soluble it actually is. Supposedly bismuth ammonium citrate is soluble in water, and someone was selling an old bottle of the stuff on ebay for $10 or something like that.

 

There's a company called "Bio Basic" (in Canada) that sells 100 grams of bismuth citrate for $8.00.

 

There's also a method for producing Bi2O3 called the citrate-gel method which uses bismuth nitrate and citric acid, which involves a temperature of 400 degrees C. I also see people selling the nitrate on ebay.

Edited September 14, 2014 by jpsmith123