Tuesday, October 16, 2007

Ceric oxide, iron oxide reaction mechanisms

I will make this short:

Ceric oxide is an oxygen conductor. The same as Platinum or Palladium is for hydrogen conductance, the same is ceric oxide for oxygen. You can deplete oxygen on one side of the crystal and supply it on the other. The crystals of ceric oxide during reactions can have precise composition of CeO2 to CeO1.5 - making it effectively Ce2O3 - but here we talk about the whole range, not a single oxide. This is extremely useful when using the nanometric powder which consist of interconnected crystals of basic 4nm size which form a flake of about 3-7 micrometers. This flake has very high surface area. When dispersed in diesel fuel for example which gets injected in tiny droplets with this snowflake inside, as the fuel evaporates the rest still hangs on the CeO2 skeleton. This skeleton has a very high surface area and can release oxygen and also receive oxygen, especially from nitrogen oxides, like NO and NO2.

Now iron - Fe - reacts with KNO3 at red heat temperatures to form potassium ferrate (very strong oxidiser), the ironic oxide Fe2O3 can be ignited with KOH (burns with flame?) to yield K2FeO4, or similar reaction with a mix of KOH and KNO3 (Fe2O3 + KOH + KNO3 —> K2FeO4 + KNO2 + H2O).
I saw somewhere a method how to react it with K2CO3 - which is one of the reaction products from sugar-KN burning as seen in Richard's page here.

As for the similar oxidiser MnO2:
"Fusion of MnO2 + KOH + KNO3 --> dark green managanates K2MnO4"

So, everything is possible.

Only the CeO2 reacts in similar way only with strong HNO3 to form a complex oxidiser CAN (NH4)2Ce(NO3)6 - ceric ammonium nitrate. I may try this with the AN fertiliser (as I have nothing of any purity right now :( whether it does make any difference)

In general: oxidants and oxidant precursors should be mixed and prepared together (KN+oxides) and oxygen transfer improver mixed with the fuel (sugar+CeO2).
When possible also calcinated or sintered together and pulverised after (as any normal catalyst preparation)

EDIT: The last thing I forgot to mention is the water content in the oxides. In case of the brown iron oxide, there might be the effect of accelerated foam production at high pressures perharps, or it really may be related to powder form. James Yawn uses 1-2% red iron oxed, bought al local pharmacy to increase the burn rate at atmospheric pressure about twice. In experiments made by Richard Nakka, only brown iron oxide was strong accelerant and only in case the pressure was much elevated. So, what is the ultimate accelerant? Water content? Oxide solubility in KNO3? Surface area per gram of powder? Absorbtion of the IR spectrum? All together?

The food grade Fe2O3 bought in pharmacy is likely going to be of high purity, very fine powder with no large particles, because it is used for coloring pills, gels, medications. The paint grade Fe2O3 had less accelerating properties, its purpose is to be mixed with oil for painting.

When my tools arrive:
Fe2O3 - Fepren TP-303 - not the best option, but this will be available
CeO2 - polishing grade thoriumless, high purity

mix1:(Fe2O3), mix2:(Fe2O3+KMnO4+CeO2)grinded together, mix3:(mix2 sintered in oxy flame, grinded afterwards)


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