Six-carbon containing model compounds of 1-hexanol, 1,6-hexanediol and sorbitol for the reforming were employed to study the effect of hydroxyl functional group on the thermodynamic equilibrium product distribution in a wide range of conditions of temperature (300–1300K), pressure (1–150atm) and feed composition (H 2 O/carbon=0.5–30). The increase of hydroxyl group in reactants gave rise to the increase of carbon dioxide with loss of methane in the product in the following order: sorbitol>1,6-hexanediol>1-hexanol, while the formation of hydrogen and carbon monoxide was mostly governed by the feed composition (H 2 O/carbon) and pressure rather than the number of hydroxyl group in reactants.