Sciencemadness Discussion Board

Any interest in a palladium-based catalytic chemistry kit?

Melgar - 18-8-2016 at 15:34

I recently discovered I had some money in a precious metals trading account that I'd forgotten about, and used it to buy an ounce of palladium. Of course, I don't need that much palladium, so I've started dissolving it to get the chloride salt, since that's the only way I can conceivably divide it up.

I plan to sell it on eBay, where it's been going for about $40 a gram, but I figured I'd check interest here too. Obviously, you guys could buy it for a significant discount. I could also include carbon black, copper chloride, nickel sulfate, graphite electrodes, activated alumina beads, a hydrogen-generating aluminum alloy (just add water), and potentially other reagents that are useful for palladium chemistry. I'm open to other ideas for things I could add to a palladium chemistry starter kit too. Incidentally, I'm using only chemicals from a local jewelers' supply store, so this won't be dissolved in hardware-store muriatic acid or anything.

Palladium is probably one of the easiest, most useful metallic catalysts to use, since it can perform catalytic hydrogenation (as well as oxidation) at ambient or near-ambient pressures, and does so more readily than the other two popular hydrogenation catalysts: platinum oxide and Raney nickel. It's also the cheapest platinum group metal that has wide application for use, and can be easily plated onto electrodes to make them inert to common electrolysis conditions. When looking up catalyzed reactions that could potentially be of use to me, palladium comes up more frequently than any other element, at least at pressures and temperatures that are achievable in a home lab.

So, is there any interest in a palladium-based catalytic chemistry kit, and if so, what would you like to see in one? I'm open to suggestions, and also open to trading said kits for reagents and/or equipment. I plan on using any money I make to investigate non-toxic alternatives to reactions that currently necessitate the use of mercury, so non-toxic metals that are components of low-melting-point alloys would be particularly appreciated as part of any exchange. Gallium and indium in particular, since they're the most expensive.

PdCl2

MediMan - 23-8-2016 at 20:06

Hey, I'm interested. In some of the PdCl2

How can we arrange the exchange?

Melgar - 24-8-2016 at 17:19

The only issue with doing the exchange right now is that I'm currently lacking nearly all of my lab equipment, including my milligram scale. However, I do have 500 mL of dark brown PdCl dissolved in acid! I figured a fair price would be $30 for the first gram of PdCl2, $25 for each gram after that, and a grab-bag of various useful things including but not limited to:



I'll probably have to limit this to just the US, since even shipping to and from Canada is a pain. Payments can be via Paypal, Bitcoin, or an equivalent value of useful reagents.

Arg0nAddict - 17-9-2016 at 06:29

You did buy at a bad time but save it. With us troops surrounding russia I bet metals skyrocket. I took a just below break even on gold chloride because nobody believed it I. had to have it tested which didn't cost much since they knew exactly what to compare. Still so sales. Then I tossed in a free gram of silver and that got things going. Weirdly. Personally I never Destroy coins or bars connected to a country becusee they hold more value what I look for are the home made shitty ingot and work up from there. I have a thing for coins though and I prefer silver. Nothing pretty like a sealed and never circulated walking liberty. Proof coins are nice but seem fake to Me even though I know they are not, the natural look of a coin just minted is a favorite. I'd be interested in trading I just spent all on inventory

Magpie - 14-10-2016 at 12:16

I received the 10%Pd/C gratis from Billy in LaJolla a few days ago as promised (see my post in Preparation of Succinic Acid). As suggested by Dr Bob, today I tested its activity using methanol. Then I tested it using propane. The results were negative. My son made three short movies of this testing. So, from the studios of Mr Ardipithicus, here they are:

https://youtu.be/enEykN7nbsQ
https://youtu.be/PSTSCmskPd0
https://youtu.be/lCDD7KWRaB4

As indicated in the last movie, if you have any suggestions for further tests, or corrections to my tests, please let me know.


[Edited on 14-10-2016 by Magpie]: reposted last video - seems to work OK now.

[Edited on 14-10-2016 by Magpie]

Tsjerk - 14-10-2016 at 12:33

I would love some Pd/C! Pt I have, but only as a metal. Pd I would like to have as a catalyst on carbon. Looking forward to doing some reductions.

Is there any way to re-activate Pd on carbon? I made some grams about 10 years ago. I'm not to sure about the activity though as I never tested it, and I'm quite sure it is not active anymore either.

[Edited on 14-10-2016 by Tsjerk]

Magpie - 14-10-2016 at 19:53

It dawned me that the sulfur gas in the propane might be poisoning the catalyst. But that doesn't account for the failure to ignite the methanol (Heet).

madcedar - 14-10-2016 at 20:20

Quote: Originally posted by Magpie  
I received the 10%Pd/C gratis from Billy in LaJolla a few days ago as promised (see my post in Preparation of Succinic Acid). As suggested by Dr Bob, today I tested its activity using methanol. Then I tested it using propane. The results were negative. My son made three short movies of this testing. So, from the studios of Mr Ardipithicus, here they are:

https://youtu.be/enEykN7nbsQ
https://youtu.be/PSTSCmskPd0
https://youtu.be/lCDD7KWRaB4

As indicated in the last movie, if you have any suggestions for further tests, or corrections to my tests, please let me know.


[Edited on 14-10-2016 by Magpie]: reposted last video - seems to work OK now.

[Edited on 14-10-2016 by Magpie]


I'm glad to see you got the plastic wrapper off the bottle. :D

You could try what you are doing in reverse. Put a tiny bit of methanol into a beaker with a watch glass on top and allow some time for a methanol vapour/air mix to form. Remove the watch glass and sprinkle in a tiny amount of catalyst from your spatula. The result should be glowing catalyst particles, methanol bursting into flames and a potential cardiac arrest. I'm not saying it's a safe test.

Fleaker - 16-10-2016 at 10:53

Magpie,

Those Pd/C catalysts usually only set stuff alight after they've been saturated with hydrogen.

Magpie - 16-10-2016 at 10:57

Good to know! Thanks.

Could this be done be purging the bottle with H2 then keeping it under H2 balloon pressure for some time?

Fleaker - 16-10-2016 at 11:34

That should do it.

One customer has a palladium catalyst that contains about 700 lbs of palladium on 15 tons of carbon. When they discharge it from the reactor it has to be passivated for months with oxygen to remove absorbed H2. It's a common practice!

Morgan - 16-10-2016 at 12:02

Pd 1.25% on carbon rod bits, and Pd 0.5% on alumina pellets - the two on the right in both photos will both heat up if misted with methanol from a finger pump sprayer. But if you drench them in alcohol, they don't get a chance I think because the air can't get to them as much. These bits and pellets made the petri dish way too hot to hold if you placed it in the palm of your hand but they never glowed in this environment and they are slow to heat up.
http://www.sciencemadness.org/talk/files.php?pid=202104&...
http://www.sciencemadness.org/talk/files.php?pid=202104&...
Better perspective of the Pd pellets.
http://www.pulse-jets.com/phpbb3/download/file.php?id=13733&...
As an aside some 1% platinum on alumina powder.
https://www.youtube.com/watch?v=h3lS3TBuntw

One thing you might try to get palladium on carbon to get going is to heat it strongly and then let it cool down to room temperature and then try to mist it with some methanol. Sometimes this will activate it. You might try just putting a little methanol on it and lighting that and let it cool. There's a platinum catalyst lighter that sometimes exhibits this quirky property if it's sat without use for some time. Also if it's very humid out this can slow the effect of my platinum on alumina powder when sprinkled into a jar containing methanol vapor, the tiny dust particles don't glow red hot as quickly. And methanol that has absorbed too much moisture from the air will often leave a watery residue say if you burn some on the pavement and that can inhibit the pellets. This is also true with the Pt catalyst lighters, the methanol saturated cloth/wick eventually builds up humidity either from combustion or just being repeatedly exposed to the air - the wick will be plenty moist but not as perky as fresh methanol in getting an ignition to take place, but I digress.
I recall wishfully trying propane with my platinum catalyst and it was a no go if starting from room temperature. But Pt or Pd can ignite hydrogen this way.
https://www.youtube.com/watch?v=I45xfo-JvTk

One last tidbit from the past.

Expt. 81. Absorption of Hydrogen by Palladium.—One of the simplest ways of causing palladium to absorb hydrogen is to decompose acidulated water by means of a voltaic current, whereby two gases are evolved—hydrogen at one pole or electrode and oxygen at the other. If the terminals of the wires leading from the voltaic battery are made to be strips of thin palladium foil, the strip attached as the " negative " electrode, at which the hydrogen is disengaged, will absorb most of the liberated gas, and in so doing will increase somewhat in dimensions, the metal swelling as it absorbs the gas, much as water does when it absorbs ammonia (Expt. 74). When a strip of palladium foil, or a thin palladium wire, is fully charged with hydrogen in this way, a slight elevation of temperature suffices to expel a little of the occluded gas; in consequence the charged metal can be used as a candle or torch; when the end is held for a moment to a light the heat expels some of the hydrogen, which takes fire and burns ; the heat thus produced causes morehydrogen to be liberated, so that the flame keeps burning for some time, the metal being clothed with a very pale flame, almost invisible in daylight, somewhat as though it had been dipped in strong alcohol, and then fired before the spirit evaporated.
http://www.sciencemadness.org/talk/viewthread.php?tid=16329#...

[Edited on 16-10-2016 by Morgan]

Magpie - 16-10-2016 at 12:53

Thanks for this Morgan. I will try some misting.

Dr.Bob - 18-10-2016 at 06:15

I have seen Pd/C set MeOH on fire a few times. Most times were before hydrogen touched catalyst, and with old bottles. Often the catalyst is shipped wetted with water, and will dry over time, so perhaps let a sample of the catalyst sit out somewhere fire safe and dry overnight, then try it. 10% is much more reactive than 5%, much more than twice as likely to catch fire.

The challenge is that it was not done on purpose, so hard to rreplicate perfectly, but the idea of putting a small amount of MeOH in a beaker, waiting a while, and then adding a small amount of pd/C to it sounds like what was done wrong. I often weight the catalyst first, then purge with N2, then add the ethanol solution of compound under inert gas. If the reaction is complex, I might have to add the Pd/C last, in which case I make sure the solution is well purged/sparged with N2 first, then add the catalyst (preweighed in a vial in one quick portion under N2. But just try the catalyst if all else fails.