http://science.howstuffworks.com/question159.htm
Hydrogen peroxide and silver really do react that way. The hydrogen
peroxide has to be extremely concentrated for it to work — around 90 percent,
compared to drug store hydrogen peroxide that is sold at a
concentration of 3 percent. If you have a 90-percent concentration like
that, hydrogen peroxide makes a great rocket propellant!
Hydrogen peroxide’s chemical formula is H2O2. When it comes into contact with silver, the silver acts as a catalyst. The reaction frees the extra oxygen atom
to produce water, and also generates a lot of heat. The heat turns the
water into steam, which the engine can eject at a very high speed
through a rocket nozzle.
Used in this way, hydrogen peroxide is a monopropellant. Compared to a normal rocket engine
that burns two different chemicals (a fuel and an oxidizer), a
hydrogen-peroxide engine is very cool and relatively safe. It is also
very easy to throttle.
This alone is enough reason to buy and hold physical silver.