Well, Greg, to be honest, I shot from the hip. I did a search on Google, using <sulfur platinum catalyst> There are abundant articles on the poisoning of platinum catalysts by sulfur. However, sulfur dioxide, with oxygen present (the expected situation in diesel exhaust), does not harm platinum and in fact platinum is the catalyst used in sulfuric acid manufacture. Sulfur dioxide is converted to sulfur trioxide in engine exhaust in this case.
In a reducing atmosphere, below about 200 degrees C, platinum forms a compound with sulfur, PtS2. (Handbook of Chemistry and Physics) You can expect that repeated exposure of a platinum-coated material to this condition will result in removal of the platinum coating. I noticed that one researcher states a small amount of sulfur is needed for a platinum-based catalyst /trap that removes soot from diesel exhaust. I hope I have redeemed myself from the careless remark. Ernie Rogers > Date: Thu, 19 Aug 2004 14:55:59 -0600 > From: "Greg Harbican" <[EMAIL PROTECTED]> >Subject: Re: Re: NOx and catalytic converter use. > >Please show where sulfur oxidizes members of the platinum family. > >Greg H. ----- Original Message ----- From: [EMAIL PROTECTED] To: biofuel@yahoogroups.com Sent: Thursday, August 19, 2004 12:02 Subject: [biofuel] Re: NOx and catalytic converter use. Sulfur attacks the catalyst. Sulfur oxidizes most metals. [Non-text portions of this message have been removed] ------------------------ Yahoo! Groups Sponsor --------------------~--> Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. Now with Pop-Up Blocker. Get it for free! http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/FGYolB/TM --------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://infoarchive.net/sgroup/biofuel/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/biofuel/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
