In the light of the thread " more thoughts on catalysts" and on rereading
this post below it occurred to me that there are two iron oxides commonly called
red and black. The formation of steel from iron alloy seems to assure that it
produces red oxides which flake off easily and don't continue to protect the
metal, it rusts to ruin. Another formation of iron alloy called wrought iron
produces a black oxide which protects the metal, it don't flake off.
I think if you wanted to use iron as a catalyst you would have to experiment
far up the production chain at the smelting process. Isn't it normally smelt
with coke? The reaction separating the iron from the ore adds certain other
elements that might not be good for a catalyst. I don't think common grades of
iron will do the job (catalyst), and I'm not certain other grades will either.
Sean Patrick Daly wrote:
> Not to burst any bubbles, but I have tried screens made from mild steel
> (available at your local hardware store). I found (at room temperature) that
> the steel screens produced a pathetic reaction. The same screens, coated in
> silver, react violently, but for the short period of time it takes to
> blow/melt the silver off my screens.
>
> I have not tested "heating" the steel screens, but I know that at 85% H2O2,
> once the silver is gone, my engine just sprays steamy H202 out the rear with
> pretty much no chamber pressure (mind you, the screens are heated to at
> least 1300 degrees at this point, but stripped of 90% of the silver). So,
> steel at 1300 degrees with 85% H2O2 did not seem to work for me, but I have
> not tested this extensively...
>
> To me, steel seems useless (except when used in tandem with silver in a
> Cat-pack), but I may be wrong. One could theoretically try different
> forms/alloys (Ag-Steel/Ni-Steel?) but I suspect that it would still be a
> fairly poor catalyst compared to Silver.
>
> I have in the past tried a liquid catalyst with Iron Oxide suspended, but
> mixing before engine firing became a pain in the ass, and I found it
> impossible to get a even reaction.
>
> Sean
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:erps-list-admin@;lists.erps.org]On Behalf Of Michael Free
> Sent: Wednesday, October 30, 2002 6:47 AM
> To: Sean R. Lynch; ERPS; Pierce Nichols
> Subject: Re: [ERPS] KISS III Propulsion System Test
>
> If iron oxide is a good enough catalyst for an operational engine, wouldn't
> it be easy to ensure that there's enough steel in the chamber to supply
> enough oxide for a mission in a replaceable "pack"? Remember, mild steel is
> cheap... *and* easy to work, and IIRC less dense than any of the other
> metals mentioned. I'm thinking either a compressed pack of cheap window
> screen or to be more advanced maybe a "block" of steel with passages
> bored/cast through, like a honeycomb (which just for arguments sake, will
> increase in surface area as it wears...)
>
> Mike Free
>
> ----- Original Message -----
> From: "Pierce Nichols" <[EMAIL PROTECTED]>
> To: "Sean R. Lynch" <[EMAIL PROTECTED]>; "ERPS" <[EMAIL PROTECTED]>
> Sent: Tuesday, October 29, 2002 12:54 AM
> Subject: Re: [ERPS] KISS III Propulsion System Test
>
> > At 09:34 PM 10/28/2002 -0800, Sean R. Lynch wrote:
> >
> > >For example, according to Dan's tests platinum only works well at high
> > >temperatures. I was hoping we could use something a little less
> > >expensive, though. Stainless steel maybe? :) Iron oxide is a catalyst.
> >
> >
> > Stainless steel doesn't form oxides unless seriously provoked --
> > better to go with a mild or carbon steel of convenient properties.
> However,
> > it would be a sacrificial catalyst, as iron oxides are not tenacious and
> > will be carried away at some rate best determined through experiment. It
> > appears that most, if not all, transition metal oxides are at least
> > somewhat catalytic. All of the catalysts for peroxide that I have heard
> > tested or floated in any way are transition metals or their oxides.
> > Anecdotal evidences (such as the requirement for 'burning in' a silver
> > pack) indicates that it's the oxides that have the real catalytic action.
> I
> > think the proper approach to catalyst development is to read through the
> > tables and select those oxides that have otherwise convenient properties
> > and test their activity and resistance to poisoning. The actual working
> > catalyst should be a ceramic composed of the best catalysts found in the
> > search.
> >
> > -p
> >
> >
> > Mars or Bust!
> > www.marssociety.com
> >
> > _______________________________________________
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>
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>>>>>>>>>>>>>>>>----<<<<<<<<<<<<<<<<<
........ Alex Fraser N3DER .........
......... [EMAIL PROTECTED] .......
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