Precipitating palladium help needed

[anachronism]

Niels.
I'm a bit confused as to what you do.

First you dissolve the Pd in AR and then drop it as Hydroxides by lifting the pH to 10.

I fail to see the reasoning behind this.
If I'm not mistaken, the Formate reduction can be done without the Hydroxide conversion.

Agreed, the purpose of the initial hydroxide conversion is to separate out the Silver contamination from the Palladium.

 

[Yggdrasil]

Agreed, the purpose of the initial hydroxide conversion is to separate out the Silver contamination from the Palladium.

Since he is dissolving already pure Pd sheets, I still fail to see the purpose.

 

[anachronism]

Since he is dissolving already pure Pd sheets, I still fail to see the purpose.

I agree completely. On another note I'm sure Lou once told me that you can drop Pd clean, out of a Nitrate solution using Ascorbic. @Lou can you comment?

 

[niels-chemist]

Since he is dissolving already pure Pd sheets, I still fail to see the purpose.

The purpose of what?

 

[Yggdrasil]

The purpose of what?

Did you read the other posts?
The purpose of converting to Hydroxides.
I really can't see a benefit of that when you are dealing with a pure solution.

 

[niels-chemist]

Did you read the other posts?
The purpose of converting to Hydroxides.
I really can't see a benefit of that when you are dealing with a pure solution.

I´m not aware that Pd will precipitate just as efficiently straight from AR as it does from a hydroxide suspension

 

[niels-chemist]

You can add HCl and Zinc powder during stirring, it also works fine.
Or even Al powders.
Or redissolve and use Formic on that.

View attachment Zn.mp4
Here I added Zn powder to a pH = 1 solution with Pd2+ present. As you can see not a lot is happening. Any clue what I'm doing wrong?

 

[Yggdrasil]

View attachment 63396
Here I added Zn powder to a pH = 1 solution with Pd2+ present. As you can see not a lot is happening. Any clue what I'm doing wrong?

Did the Pd powder dissolve?
Hard to see on a phone.

Edit to add:
I see it now, have you deNOxed it in any way?

 

[niels-chemist]

Did the Pd powder dissolve?
Hard to see on a phone.

Edit to add:
I see it now, have you deNOxed it in any way?

I first made it alkaline with NaOH....

 

[Yggdrasil]

I first made it alkaline with NaOH....

How did you acidify it?

Edit to add.
Do you know what impurities are in the Pd?

 

[niels-chemist]

How did you acidify it?

Edit to add.
Do you know what impurities are in the Pd?

36% HCl to pH 1. Impurites: don´t know yet. Still have to have a sample analyzed. These solutions are combined reaction mixtures that should contain Na+ as the only other metal ions and some organic stuff that shouldn´t interfere and as anions only OH- / Cl-

 

[Yggdrasil]

36% HCl to pH 1. Impurites: don´t know yet. Still have to have a sample analyzed. These solutions are combined reaction mixtures that should contain Na+ as the only other metal ions and some organic stuff that shouldn´t interfere and as anions only OH- / Cl-

The formate reduction you used, did not give you the purity you wanted?
I still do not see the point of dropping as Hydroxide, the only thing you accomplish is to increase the amount of Na⁺ ions in the mix.
Until you know the make up of the impurities and can device a plan to get rid of them, anything you do will be based on guesswork and assumptions.