[klodolph]

Someone can break out their chemistry references, but I think N₂O is probably not workable as a fuel (or at best, not very good). It forms naturally in internal combustion engines, from air, at the temperature and pressures found in engines, given O₂ and N₂. If something has the habit of forming in an engine, I don’t think you could use it as fuel, but my thermodynamics is a bit too rusty to do any kind of ELI5 and I could just be wrong here. At the very least, it would be difficult to use or inefficient.

It decomposes into N₂ and O₂ at normal atmospheric temperatures and pressures, outside an engine.

[topaz0]

You're probably thinking of NO2, which is indeed a pollutant that results from overly hot combustion in air. N2O is in fact used in engines, but it is not the fuel -- rather it is a supplementary oxidizer, which allows you to burn more fuel and therefore produce more power than you could if you only had the oxygen from air. At any rate, that means using N2O won't be a solution to the aircraft fuel problem -- you'd still need a combustible fuel for it to oxidize.

[DoctorOetker]

You are correct that N2O is the "nitro" afterburner used in different systems.

But the reaction 2 N2O => 2 N2 + O2 is very exothermic, in fact it is explosive (but not in the burning sense, since its autodecomposition). However adding a small amount of ethanol makes N2O stable so that sudden shocks or compressions don't result in initiating autodecomposition or explosion.

To power an engine one doesn't necessarily need to burn, or a redox reaction to happen, the reaction just needs to be exothermic and N2O is very exothermic.

[topaz0]

I stand corrected.

[klodolph]

Damn, yes, I mixed those up.