“at a buck or two a bottle Hydrogen Peroxide is a good cleaning supply to buy by THE CASE (for the coming lean times)”
You are correct in that hydrogen peroxide is an incredibly useful (and cheap) item, but I believe it degrades over time, so if you are buying in bulk, you probably should refrigerate it.
H2O2 is unstable as you suspect. The solution you buy at the drugstore is about 3% peroxide the rest being water. It (the peroxide) breaks down into a water molecule and free oxygen which is the bactericide. The breakdown is accelerated by sunlight and higher temperatures. It is best stored in cool dark conditions. That will slow the decomposition but it will eventually turn completely back to water over time. Long term storage is a rather relative thing.
Higher concentrations are commercially available with 30% being used by beauty parlors to create "peroxide blonds". It is a powerful bleaching agent and about as high a concentration as you would normally find in daily commerce. When concentrated to 70 to 98% the instability is dramatically increased. It decomposes in an explosive exothermic reaction which instantly boils the water and produces copious quantities of steam and oxygen which can be further heated by injecting a liquid fuel (diesel oil) or passing it over a combustible solid (butyl rubber).
Toward the end of WWII the German Navy built an emergency power plant for their submarines which used this reaction to generate steam which was passed through a single pass turbine and then vented outside the hull. The turbine generated some 3000 horsepower for thirty seconds and left an enormous bubble where the sub had been, allowing an escape from surface ships dropping depth charges. The bubble serving to spoof the sonar. The device was not popular with crews as the high concentration peroxide was a very dangerous chemical to be stored in the confined spaces of a submarine. I believe they also used it as an oxidizer (T-Stoff) along with a methanol/hydrazine fuel blend (C-Stoff) use to power the ME-163 rocket powered interceptor plane fielded near the end of WWII. The ME-163 was notorious for frying it's pilots, not a real confidence builder.
There is a self taught Mexican mechanical wizard who builds peroxide rocket propelled drag racers, motorcycles, helicopters, and one man rocket belts. His website is http://www.tecaeromex.com/ingles/indexi.html
Reacted with acetone under suitable conditions, H2O2 becomes "Mother of Satan", a favorite of terrorists. Do NOT try this at home as it will prove to be very bad ju-ju (next of kin may be unable to id the body!! You have been warned!).
Regards,
GtG