You'll find here some stuff related to rocket propulsion using hydrogen peroxide (H2O2). For the newcomers, hydrogen peroxide is a colourless, dense (1.36 at 85%), corrosive liquid, storable at ambient temperature/pressure, that can be used as oxidizer or monopropellant in rocket engines. It's only useful at high concentrations (> 80%), but unfortunately, such concentrated product isn't commercially avalaible, and has thus to be manufactured from lower concentration product. I personnally achieve this by selective evaporation, at moderate temperatures for safety. This is a potentially dangerous operation, since peroxide vapours can be explosive, and it should surely not be undertaken by anyone.
I've started designing an hypergolic hybrid rocket motor, which burns polyethylene and uses 85% hydrogen peroxide as oxidizer. Hypergolic ignition is achieved using a consumable catalytic bed, mainly made of potassium permanganate. It decomposes the peroxide as soon as it is injected in the combustion chamber, creating a stream of superheated steam and oxygen, which then causes the PE grain to auto-ignite. As far as I know, this motor is (one of ?) the first amateur hydrogen peroxide hybrid in the world.
A small cheap demonstration motor was first built, and fired successfully a few times. A lot of extra subsystems were then needed to make testing of bigger motors easier and safer, so it took a lot of time; two bigger motors are now in the static test phase.
Other's H2O2 work
Amateur H2O2 propulsion isn't common; that can be explained both by the difficulties of manufacturing high concentration product, and by the risks associated with its handling (it is notably very corrosive). However, several groups around the world have done interesting achievements in the past few years (if I forgot someone, tell me !).