The triacetone triperoxide (TATP) that has been mentioned, is a solid precipitate from the mixture of acetone and hydrogen peroxide with an acid catalyst. Wikipedia has instructions for making this stuff, and it is very dangerous to make, requiring cooling to control the process and prevent explosions during the mixing.
But since we are discussing the idea of terrorists mixing this stuff on a plane, in order to destroy the plane, would they care if it exploded during the mixing process? Would the premature explosion of the mixture produce an explosion of the same intensity as the completly precipitated and dried crystaline solid?
Another explosive involving hydrogen peroxide uses methyl ethyl ketone, insteard of acetone. This produces a liquid (MEKP) that is explosive. The production of either (TATP or MEKP) of these explosives appears to involve a substantial amount of equipment, in addition to the liquid ingredients, and quite a long time to process into an explosive.
Other binary explosives use toxic components such as hydrazine.
I think it is highly unlikely that a terrorist could actually make an explosive during the flight, using the small cramped space available in the porta-potty sized restroom on the plane.
It would appear to be more likely that an explosive liquid be smuggled onto the plane, than be created on the plane. Highly sensitive liquid explosives that do not require an explosive initiator, would be likely to explode before being placed on the plane, so some type of initiating device (blasting cap or other) would also have to be smuggled on board for the less sensitive explosive.
I suspect that the information that the government has made public is intended to deceive the public; the actual nature of the explosive material, and how it would be placed on the aircraft and detonated, is information that we do not need to know, and if made public, might tempt other people to try in a copycat crime.
The government saying that the attempt would be made with TATP may even be intended to sucker wannabe terrorists into blowing themselves up, while trying to create this homemade explosive the Palestinians have nicknamed "Mother of Satan". That nickname is apparently due to the difficulty in creating it, without having it explode during the process. Once it has been sucessfully created, it still poses extreme risks, since it is sensitive to heat and pressure, and may self detonate just from its own weight.
I am very sceptical about this whole reported 'binary explosive mixed on aircraft' story. I think it is deliberate misinformation provided to the public, and the motive for that misinformation is unclear.
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