The Reduced Mechanism
The 4-Step reduced mechanisms were derived from a start-mechanism by introducing
CH2OH, CH2O, CHO, HO2, OH, and O in steady-state.
| Number | Global Reaction |
| I | CH3OH + 2 H -> 3H2 + CO |
| II | H2O + CO -> H2 + CO2 |
| III | 2 H + M -> H2 + M |
| IV | 3 H2 + O2 -> 2 H2O + 2 H |
By introducing the water-gas shift reaction is in equilibrium,
where
c represents the water-gas reaction constant, the three-step reduced
mechanism can be written as
| Number | Global Reaction |
| I | CH3OH + 2 H + [(3c-1)/(c+1)]CO2 ->
[4/(c + 1)](H2 + cCO) + [(3c - 1)/(c + 1)]H2O |
| II | 2H + [c/(c + 1)]CO2 ->
[1/(c + 1)](H2 + cCO) + [c/(1 + c)]H2O |
| III | O2 + [3/(c + 1)](H2 + cCO) ->
2H + [(2 - c)/(c + 1)]H2O + [3c/(c + 1)]CO2 |
If a steady-state approximation for H is introduced, then there
results the two-step reduced mechanism
| Number | Global Reaction |
| I | CH3OH + O2 -> [(1 + 2c)/(1 + c)]H2O
+ [1/(1 + c)]CO2 + [1/(1
+ c)](H2 + cCO) |
| II | [1/(1 + c)](H2 + cCO) + (1/2)O2 ->
[1/(1 + c)]H2O + [c/(1 + c)] CO2 |
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