moopthemighty
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Posts: 2
Registered: 10-6-2013
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Mood: catalytically inert
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platinum electrodes, questions and ideas
I have some platinum I wish to turn into some electrodes. I was wondering if a solution of NH4NO3 + H2SO4 + NaCl in the proper amounts at STP (or
between standard and whatever I begin to feel unsafe applying to my glassware) would make a suitable electrolyte solution for dissolution of minute
amounts of platinum for the process of platinizing a larger piece
I did a few experiments and noticed some gas evolution and discoluration of a reddish to yellowish/black nature on the sample of platinum, some was
easy to wipe off with my finger, other parts required some emery cloth to polish off.
I used a wall wart capable of 12v at 1 amp with an inline variable resistor (log, 0-10k) and a carbon electrode, tried using platinum as both the
anode and the cathode.
I noticed a change in color of the solution (the H2SO4 was discolored I'm assuming from oleum... liquid fire... I don't like chemical suppliers so
bear this in mind... some impurities are present) It went from a reddish typical from a nitration mixture with impure 99% H2SO4 to a lighter yellowish
red.
It was NOT gassing off NOx and the characteristic smell of the solution was more of the HCl and almost none of the fearsome smell of HNO3 was
present... upon returning to the lab from an hour, the smell had a distinct note of it though so both species were present in the solution.
(I know... no fume hood, don't hate me I'm working on it... smaller living area than I'm used to)
I tried this at -5C , room temp on a warm summer night, and 100F, all the reactions were the same or too similar to make note of.
How preferential is the reaction kinetics to the formation of sulfate vs nitrate vs oxide vs chloride?
I'll have more to add but I just got off work and am in the process of getting ready for another day 
Thanks, I've been reading for a long time anonymously (2005 ) but this is the
first post here... something about being a kewl and knowing it...
long live the practice of rogue science!
Edit: would this inadvertantly form the ammonia complex of chloroplatanic acid? Should I use another nitrate salt?
[Edited on 10-6-2013 by moopthemighty]
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12AX7
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Registered: 8-3-2005
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Mood: informative
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Yes, you probably have ammonium hexachloroplatinate, or an ammonia complex, which as I recall, is poorly soluble, which would explain the dark residue
on your metal.
You have to get all that stuff into solution before any will cross from anode to cathode. Until then it's just a lot of bubbling.
Tim
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moopthemighty
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Registered: 10-6-2013
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Mood: catalytically inert
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so if i were to place a fine powder of this into sintered glass filter and heat via torch or nichrome while passing H2 through the filter I could
obtain the platanic acid for plating?
anything simpler?
I assume just by heating the precipitate I could obtain PtCl2 catalyst but the objective is STP hydrogenations and per/chlorate production with a
serious course of investigation on the isolation of precious metals for trade so it's electrolysis I'm interested in.
Could I put a nitrate salt in HCl+H2O for a poor man's aqua regia and thereby dissolve the PtCl2 for plating?
Would piranah solution work to oxidise the platinum chloride to PtO2?
Would piranah solution be a viable alternative to produce PtO2 directly from Pt? Would it form a sulfate in any side reactions?
would I have to add anything to the ammonia/platinum salt to ensure no undesirable compounds remain in the flame reduction?
please do bear in mind I'm limited to procedures without a fume hood at the moment and my education has gaping holes so bear with me please
[Edited on 11-6-2013 by moopthemighty]
[Edited on 11-6-2013 by moopthemighty]
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Pulverulescent
National Hazard
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Registered: 31-1-2008
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Mood: Torn between two monikers ─ "hissingnoise" and the present incarnation!
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'Some ongoing research into Pt plating . . .
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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