Moriarty (Stranger)
01-29-02 19:39
No 262577
      Reclaiming PdCl2?  Bookmark   

Does any body know anything about reclaiming PdCl2 after using it as a cataylst in the wacker oxidation using p-benzo.?  I've only bought it once, but now that I've got to buy it for a second time I'm starting to think I should have been reclaiming it all along.  No shit, huh?

Okay.  Here the plan I have.  Excuss me if it's a little crude, I just came up with it.  The PdCl2 should be in the aqueous layer after the reaction is flouded with slightly acidic water.  After separating the goods from the aqueous layer my plan is to dry in a rbf under a vacuum and simply wash several times with carbon tet, dcm or chloraform.  PdCl2 shouldn't be particularly soluable in any of these.  Or is it.  Major question.  Will PdCl2 be soluable in slightly acidic h2o (I'm sure it is)?

Little help from any body who reclaims their catalyst.  I know your out there.
(Hive Bee)
01-29-02 22:44
No 262652
      Re: Reclaiming PdCl2?  Bookmark   

No one I think has been able to reclaim it in the benzo wacker with any positive results. Its more trouble than its worth for the benzo wacker. It is possible to recover from other wackers but not the benzo. Maybe you could do it on a large scale but why do a benzo on a large scale.
01-29-02 22:55
No 262659
      Re: Reclaiming PdCl2?  Bookmark   

I will once I order some more, but out of curiousity, why not use p-benzo?  I really don't know.
(Hive Bee)
01-30-02 00:59
No 262689
      Re: Reclaiming PdCl2?  Bookmark   

The benzo is not really practical for very large scaleup. For one too god damn messy i.e cleanup is a bitch. Swim dosnt think you can really recover the palladium from the benzo with any reliable method. Swim tried once. Didnt get enough to make it practical or wasnt even sure if it was any good.
If you want try ,try saving all youre waste first then leting it sit in distilled water (lots of it) for a couple of days weeks even. This will dissolve youre quinone crystals and seperate most of youre  waste. Youre palladium will fall to the bottom with a bunch of other shit too. seperate this and proceed to wash it some more to try and get rid of any other solids and nasties in it. When you think you have a lot of the other shit all gone then run it through a catalyst sieve a to try and get the palldium. dissolve in aqua regia and distill under vacuum making sure the aqua dosnt get out of control till all is gone. You will end up with a brick on the bottom that should be palladium chloride.
Swim dosnt know if this will work for this. Tried once and did get something that looked like PdCl2 but never found out for sure if it was. Swim came up with this after talking to a manufacturer about thier methods of paladium and paladium recovery. Like Swim said better have a lot of it to make the effort worth while and for something not proven. Hope you have a lot of time on youre hands and dont mind elbows in buckets of hazardous waste.
Most bees end up with a lot of thier paladium in thier flask when they distill too do to lousy cleanup methods. Ads to the black tar that does not want to go away.
01-30-02 06:11
No 262728
      Re: Reclaiming PdCl2?  Bookmark   

By UTFSE Post 174712 (lugh: "Re: Recycling of Palladium", Chemistry Discourse) Post 177284 (lugh: "Re: Recycling of Palladium", Chemistry Discourse) & Post 75765 (lugh: "Re: PdCl2 synthesis", Methods Discourse) came up, if you take the time to look you will find more smile