This is basically an alternative to storing oxygen in gas tanks.
Hydrogen peroxide would be stored in a tank with a catalyst dipper (e.g. platinum) that can be immersed to control the rate of oxygen production.
Even relatively low concentrations of H2O2 create a surprising amount of oxygen, e.g.
6% concentration H2O2 produces 20 liters of oxygen for each litre of hydrogen peroxide decomposed (according to wikipedia).
Of course this would create far less oxygen compared with a regular gas tank of equal size, but there may be some situations where a gas tank is not desirable. For example it would be relatively easy to refill a tank with hydrogen peroxide compared to filling a tank with oxygen. Also, it might be safer in some situations.
Although I have classified this idea in sport:water:underwater I doubt this would be a suitable application; I just thought I may as well stick this idea with the scuba tank ideas.