?Go for COUPLED CHEMICAL REACTIONS
Reduction of iron oxide by CO is an example of
using TWO reactions coupled to each other in order
to drive a thermodynamically forbidden reaction:
Fe2O3(s) ? 4 Fe(s) + 3/2 O2(g) DGorxn = +742 kJ
3/2 C(s) + 3/2 O2 (g) ? 3/2 CO2(g) DGorxn = -592 kJ
with a thermodynamically allowed reaction:
Fe2O3(s) + 3/2 C(s) ? 2 Fe(s) + 3/2 CO2(g)
BUT DGorxn < 0 kJ for T > 563oC
See Kotz, pp933-935 for analysis of the thermite reaction