Cat Converter Recovery With Nitric

[jaun]

Would it work to put the honeycomb in hot nitric to dissolve the palladium first, and then put the honeycomb in hot AR to dissolve the platinum? (You wash the honeycomb between acids)
You use the same acid on a few cats until it’s more concentrated.

 

[Lou]

I don't know how effective that would be because 1.) much of the Pd on the converter may be as its oxide, which doesn't readily dissolve in nitric acid (not even that much in aqua regia), 2.) much of the Pd won't rinse out with just plain water, dilute nitric acid would have to be used.

It's just easier to use aqua regia.

 

[jaun]

Yes, you’re right. That would just complicate things unnecessarily.
Thanks lou