Boudouard's reaction

Boudouard's reaction - the redox reaction of a mixture of carbon monoxide and carbon dioxide, remaining at chemical equilibrium at a given temperature, involves disproportionation of carbon monoxide to carbon dioxide and graphite: 2 CO ⇌ CO2 + C Standard enthalpy of Boudouard reaction for different temperatures

The formation of carbon dioxide and carbon in the Boudouard reaction is an exothermic process throughout the temperature range. However, the standard enthalpy of this reaction becomes less negative as the temperature increases.

Although the enthalpy of CO formation is greater than the enthalpy of CO formation, the entropy of formation is much smaller. As a result, the standard free energy of CO2 formation from the elemental elements is almost unchanged and independent of temperature, while the free energy of CO formation decreases with temperature. At high temperatures, the reaction going to the right is therefore endoenergetic, favoring a reverse reaction in the CO direction, although the reaction going right is still exothermic.

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