What is the most compact way to store Oxygen?

What is the most compact way to store Oxygen? Perhaps I should qualify that as being at room temperature since the most compact form of oxygen is probably liquid oxygen. At room temperature would it be better to store it as rust or compressed air or something else, like hydrogen peroxide?

• Degenerated matter ;) – Mithoron Dec 17 '15 at 12:10
• Rust? Why not water, then? Or... wait, your body stores a good deal of oxygen, albeit in a chemically bound form. What exactly do you want? – Ivan Neretin Dec 17 '15 at 12:47
• @IvanNeretin I think the question is pretty clear. If an organic compound is the most compact way to store water, then what is that compound? Water is a bad answer because hydrogen pyroxide (which I already mentioned) stores oxygen more compactly than water. Did you even read the full question. – Shaka Boom Dec 17 '15 at 12:53
• @ShakaBoom Did you even write the full question? If you are really interested in packing as many as possible atoms of O in a given volume, regardless of the energetic factors (this kinda strikes me as odd, but... none of my business, really), then indeed $\ce{H2O2}$ (about 65 moles of O per 1 liter) is a pretty strong contestant and definitely better than water (55 mol/l). However, $\ce{H2SO4}$ (molar mass 98, density 1.84) is even better than that. – Ivan Neretin Dec 17 '15 at 13:06
• Nitrogen Dioxide would be the best as it is liquid and will spontaneously decompose in the presence of the right catalyst – A.K. Dec 17 '15 at 13:17