[bryanh]

interesting conversation, I know that thermite works by mixing a metal oxide with a more reactive pure metal and provided enough activation energy is supplied the oxygen transfers over to the more reactive metal. The OP made me think, could this be done with CO₂?

[HP]

Also interesting is  the Sabatier reaction where carbon dioxide is catalytically activated in the presence of hydrogen, which fully
hydrogenates the adsorbed carbon species to methane, with accompanying water formation:
CO2 + 4H2 ? CH4 + 2H2O
This reaction is moderately exothermic, H° = -165-kJ/mol.
The stoichiometric reverse water-gas shift reaction, which typically operates close to equilibrium, is mildly
endothermic, ?H° = 41.2-kJ/mol:
CO2 + H2 ? CO + H2O (2)
This process is commonly used to tailor the hydrogen concentration of mixed syngas streams in industrial operations. Due to its reversibility, however, maximum conversions and selectivities are typically governed by equilibrium. Typical water-gas shift catalysts are used but at higher temperatures.
And yes CO2 may react with some Me-oxides (i am not sure for Fe2O3) at high temperatures when it could passes oxidation properties.

[HP]

And one more interesting really decomposing reaction of CO2 (see as dry ice!) with Mg:
2 Mg(s) + CO2  2 MgO(s) + C(s)
http://www.ilpi.com/genchem/demo/co2mg/index.html
Really cool