02-13-04 10:30
No 488327
Hi Bees!
By some lucky chance i stumbled upon a discarded 25 kg barrel of somewhat old, but otherwise unused Pd/C catalyst. The only problem (except from boosting my neurotransmittor levels to the extent where no sleep is attainable for days, from pure excitement) is that the Pd contents are unknown.
Any bright ideas on how to determine this? I sure would hate having to discard 25 kg's of this nice black stuff due to lack of information
Regards
Bandil
Drugs = Fun; Drugs <> Money
(Chief Bee)
02-13-04 10:56
No 488330
The best idea is to digest a carefully weighed amount of dried Pd/C by refluxing it in aqua regia, filtering off any remaining carbon, and then precipitate the soluble Pd2+ quantitatively.
In the following prep, they precipitate with dimethylglyoxime: http://www.cpachem.com/en/Clas/Pd-grav.h
Maybe you could precipitate palladium black (free Pd metal) instead: ../rhodium /pd-cata
The precipitate is then dried in vacuo and weighed carefully (if you prepare palladium black, you need to dry it in an inert atmosphere, as the compound is pyrophoric in air).
The Hive - Clandestine Chemists Without Borders
(The Archetypical "Good Guy")
02-13-04 11:18
No 488332
Thanks a bunch for those ideas! I'll see if i can dig up some dimethylglyoxime somewhere.
Regards
Bandil
Drugs = Fun; Drugs <> Money
(Stranger)
02-13-04 11:51
No 488335
the Pd is in the form of the finely divided metal itself. like Pt, a black powder of the element is formed by reduction. it will work great in all reactions calling for Pd powder,supported Pd or Pd sponge, as long as it hasnt been contaminated by S cpds. it is hard to beelieve it was "discarded" the value is, um, a bit higher than most scrap metals. this would be like throwing away 250000. to find out how much you have, boil in HCl and evap soln, calc Pd from wt of the PdCl2.
today is my turn in the barrel
(Wonderful Personality)
02-13-04 22:32
No 488437
before dissolving it in aqua regia by heating the Pd/C together with some oxygen source in a crucible as high as possible. This will make the following step much less a mess believe me.
25kg!
lucky you
jealous I
