Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Palladium on charcoal Nope question
feynmann
Harmless
*




Posts: 29
Registered: 6-8-2008
Member Is Offline

Mood: No Mood

[*] posted on 6-8-2008 at 09:49
Palladium on charcoal Nope question


I have 20 gm of the ALdrich palladium on charcoal 5 percent .
I want to know how to regenerate the metal in the form of palladium chloride after the reaction is over .

I would like to know if someone tried it and what is the result?

I wonder if I can use the method of platinum regeneration by dissolving in aqua regia and evaporating till dryness with conc HCl several times
View user's profile View All Posts By User
Klute
International Hazard
*****




Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline

Mood: No Mood

[*] posted on 6-8-2008 at 09:58


Why go by PdCL? Dilter the catalyst off, wash it well with a solvent, 10% NaOh, water, dry and re-use!

I fyou want PdCl2, you better buy it then make it from Pd/C!




\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"

-Alice Parr
View user's profile View All Posts By User
feynmann
Harmless
*




Posts: 29
Registered: 6-8-2008
Member Is Offline

Mood: No Mood

[*] posted on 6-8-2008 at 10:31


Sorry what I want to is to regenerate Pd/c after usage to use again
I thought that obtaining PdCl2 is the only method as Pdcl2 is used to prepare Pd/C according to vogel
View user's profile View All Posts By User
DJF90
International Hazard
*****




Posts: 2266
Registered: 15-12-2007
Location: At the bench
Member Is Offline

Mood: No Mood

[*] posted on 6-8-2008 at 14:49


To prepare it, yes it is a viable option. But once you already have the palladium metal adsorbed (is this the correct term?) onto the carbon then there is no need to strip it off and then re-adsorb it... Just wash as Klute says!
View user's profile View All Posts By User
Klute
International Hazard
*****




Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline

Mood: No Mood

[*] posted on 6-8-2008 at 15:44


Have a look at US 3,214,385 for details on properly re-activating Pd/C for extended re-use (up to 20 with only 6% decrease in yield for hydrogenation of succinic acid)



\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"

-Alice Parr
View user's profile View All Posts By User
feynmann
Harmless
*




Posts: 29
Registered: 6-8-2008
Member Is Offline

Mood: No Mood

[*] posted on 6-8-2008 at 23:47


I also found a patent to regenerate Pdcl2 as it is the precursor for many other catalysts
US3210152

I wonder if there is any simpler method for regeneration of pdcl2 like that used for platinum regeneration
Procedure for platinum regenration
Platinum residues from hydrogenation reactions should be carefully preserved and subsequently recovered by conversion into ammonium chloroplatinate by the following method. Dissolve the platinum or platinum residues in aqua regia, evaporate just to dryness several times with concentrated hydrochloric acid, dissolve the final residue in a little water and filter. Precipitate ammonium chloroplatinate from the filtrate by addition of excess of a saturated solution of ammonium chloride. Filter and dry the precipitate at 100°C.
View user's profile View All Posts By User
DJF90
International Hazard
*****




Posts: 2266
Registered: 15-12-2007
Location: At the bench
Member Is Offline

Mood: No Mood

[*] posted on 7-8-2008 at 05:34


So you mean that rather than strip the Pd off of the charcoal and re-adsorb it, you're talking about recovering the (very) small amount of Pd that gets leached into the reaction mixture? This is important, as although only a very small amount of Pd is lost each time, eventually you say bye bye to your palladium :(
View user's profile View All Posts By User
stoichiometric_steve
National Hazard
****




Posts: 827
Registered: 14-12-2005
Member Is Offline

Mood: satyric

[*] posted on 8-8-2008 at 04:36


i think the thread originator has no idea what you two are talking about.



View user's profile View All Posts By User
feynmann
Harmless
*




Posts: 29
Registered: 6-8-2008
Member Is Offline

Mood: No Mood

[*] posted on 8-8-2008 at 04:37


why are u saying so???:o:o
I have been doing so for many years ....just wanna additional experience

[Edited on 8-8-2008 by feynmann]
View user's profile View All Posts By User
JohnWW
International Hazard
*****




Posts: 2849
Registered: 27-7-2004
Location: New Zealand
Member Is Offline

Mood: No Mood

[*] posted on 8-8-2008 at 17:29


The scarcity and value of Pd and Pt is also a good reason for determining whether cheaper metallic catalysts, particularly Ni, could be used for the same purpose instead.
View user's profile View All Posts By User
Klute
International Hazard
*****




Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline

Mood: No Mood

[*] posted on 9-8-2008 at 10:28


Totally agreed, copper seems like a very promising candidate too. Ni oftenr equires high temp and pressures, even though some CTH can go one well enough. But thta's not on the threads' topic unfortuanly :)



\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"

-Alice Parr
View user's profile View All Posts By User
S.C. Wack
bibliomaster
*****




Posts: 2419
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline

Mood: Enhanced

[*] posted on 12-8-2008 at 02:54


Just thought that I'd point out, and here is as good as anywhere to do so and you might not be aware, that the price of Pd has been falling precipitously in the past month, if anyone has priced Pd and been scared away in the past year. It's falling pretty fast now and on its way to losing 50% of its value in 6 months.
http://www.kitco.com/charts/livepalladium.html
If it goes back down to $200, it's time to mortgage the house and back up the truck. I last bought from Apmex, once in a while they will have a Maple or a bar within $10-20 of spot. They don't last long when that happens, because that is as good as it gets for Pd coin or bar; they often are out of stock when prices fall (esp. silver prices, large bars from them or Tulving may be available though.) or they charge a high premium over spot.

[Edited on 12-8-2008 by S.C. Wack]
View user's profile Visit user's homepage View All Posts By User
starman
Hazard to Others
***




Posts: 318
Registered: 5-7-2008
Location: Western Australia
Member Is Offline

Mood: No Mood

[*] posted on 3-9-2008 at 00:16


Recently purchased a few grams of palladium form ebay.It is in the form of small chunks of jewelers scrap,was hoping to turn it into something usable and have a few questions if anyone has time.
The (limited) information I have viewed states Pd dissolves slowly in HCl. What are we looking at hours? weeks?
Also are there altenatives to formaldehyde or the nitric acid wash for the Pd/C preparation as given in org synth? Does it have to be nitric acid?
Basically looking for a much as possible OTC for getting a finley divided metal on support of some sort.
Any suggestions much appreciated.
View user's profile View All Posts By User
not_important
International Hazard
*****




Posts: 3873
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 3-9-2008 at 00:47


The dissolution of palladium in non-oxidising acids (ie HCl) requires the addition of an oxidising agent. Air will work, but it is much faster to use elemental chlorine or bromine. Alternatively you could slowly add NaNO3 or KNO3 to the hydrochloric acid - palladium mixture.
.
View user's profile View All Posts By User
Klute
International Hazard
*****




Posts: 1378
Registered: 18-10-2006
Location: France
Member Is Offline

Mood: No Mood

[*] posted on 3-9-2008 at 06:06


You can use NaBH4 IIRC to reduce the salts to metal, but if you can't get formaldehyde..

In the platinium mirroir thread, it was suggested dissolving Pt metal by electroslyis in HCl, maybe this could work with Pd?




\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"

-Alice Parr
View user's profile View All Posts By User
cnidocyte
Hazard to Others
***




Posts: 214
Registered: 7-7-2010
Member Is Offline

Mood: No Mood

[*] posted on 12-2-2011 at 14:43


I wanna make some of this from palladium metal. I know I could dissolve Pd with aqua regia but would there be a better way to oxidise the Pd if my aim is to turn it into PdCl2.
View user's profile View All Posts By User

  Go To Top