06-29-02 13:38
No 326920
I remember reading some ref (this board) to pt catalyst as gotten from auto exhaust systems but can't seem to find it.
soooo- catalytic ceramic substrates WILL function as catalysts in hydrogenation etc reactions according to a gas phase related site.
the substrate is used as is and the gas passed thru resulting in the reactants exposure to the catalyst.
If the catalyst is poisoned by use ---the temperature will have to be raised sufficiently to burn off the poison. I understand this means placing the ceramic in a kiln (furnace) and raising the temp for lenght of time. UTSE
I don't have exact details just a general understanding but
http://mattson.creighton.edu/Microscale_
will give you an idea.
On this site there is an section talking using catalytic converter substrates for this purpose.
Anywho details or directions toward any answers will be appreciated.
OTEECEE & meeeee!!!!
(Stranger)
06-30-02 19:14
No 327445
SWIM was wondering about this as well, and has read alot here in the Hive concerning it, but seen no definitive write ups.
SWIM does know the ceramic honeycomb on the inlet side of a catalytic converter is composed of rhodium and platinum, plated to the ceramics as a reductive. The other half is an oxidizer. SWIM has been led to believe until recent years paladium was used.
Could the ceramic honey comb simply be crushed and used as a catalyst plated to carbon is used??
Determining the actual amount of Platinum and Rhodium present would seem to be the tricky part.
(Newbee)
07-01-02 07:17
No 327576
Back in the early 80's, whem precious metals like Gold, Platinum, etc. were sky high in price, I used to make extra money recycling catalytic converters. Back then they only used Platinum, and it was found in two forms: one was the honey comb used by Ford and Chrysler, the other were ceramic beads or pellets, used by GM and American Motors. One converter held either 6 lbs. of beads, or 2 lbs. of honey comb. Just to give you and idea of how little catalyst was actually in each one, I was paid approx. $4.00 a lb. for the Honeycombs, and $2.00 lb. for the beads. Part of the reason they now use Palladium, Rhodium, etc. is that Platinum went way up in price, and there were also concerns about its availability from South Africa and the other main source, the (then) Sovet Union...