stoichiometric_steve - 5-8-2007 at 03:41
this might have been discussed here, and i've actually had a procedure for this, but i've lost it and somehow, even trying TFSE didnt help. can
anybody help me out?
solo - 5-8-2007 at 06:05
Here is a thread with the information you seek......solo
http://h1.ripway.com/solo/regeneratingPd-Ccatalyst.html
jon - 5-8-2007 at 15:30
there was an article where they used basic solutions containing naoh to reactivate it.
a process operator i knew who is in the federal pen now told me they desulfurize gasoline with pd/c and the h2s poisons it so they reactivate it
using ammonia solutions so this is commonly done in industry too.
Klute - 6-8-2007 at 17:52
Exposing the spent catalyst to hydrogen would reactivate it, no? In that case, wouldn't adding a formate or other hydrogen donor in absence of a
acceptor produce hydrogen [1] and thus reactivate the catalyst? I think I remember something like that being mentionned at the Hive...
While on the subject, in the patent US4792625, they dry the reactivated catalyst with "a mixture of gases containing oxygen", which generates some
heat. What for?
Opening a bottle of nitrogen-flushed 10%Pd/C equally produces heat; does this diminish the quality of the catalyst if the protective atmosphere
isn't replaced quickly, and if the catalyst is used for a CTH and thus not directly exposed to hydrogen gas (which would supposebly strenghten it
again)?
[1] H.Wiener, Y,Sasson, J.Blum, J.Mol.Catal. 35, 27 (1986)
[Edited on 7-8-2007 by Klute]
jon - 8-8-2007 at 15:45
you have to get all the poisons off the catalyst that's the pupose of using a basic solution. hydrogen would activate the catalyst so when you add
substrate the substrate does'nt poison or deactivate the catalyst.