I dissolve the catalyst in Aqua Regia solution. after finishing the work :

I add zinc to it. The reaction is highly calorific but does not precipitate

When I add sodium bohydride, nothing precipitates, and when I add more, a white jelly-like substance precipitates.

When I add aluminum to it, the reaction is very hot, but I have a black and purple deposit.

Exactly how should I separate palladium, platinum and rhodium from the solution.

Rhodium is not important to me right now. How do I separate platinum and palladium from Aqua Regia solution?