I'm going to try burning magnesium under CO2. Magnesium is actually strong enough to directly react with the CO2 and rip the oxygen off it. It can even do this with things like water and sand, and I ...

Magnesium oxide is a dull white powder ... Some non-metals can also react with oxygen in an oxidation reaction. When burnt in oxygen, the carbon in this charcoal reacts to form carbon dioxide.