The reaction of a KOH loaded graphite powder with atmospheric pressure of steam in the temperature range 700-900K proceeds via two successive stages. During stage I, hydrogen and hydrocarbons are evolved at a high rate but no CO or CO,. This stage ceases after the equivalent of 0.5 molecules of H, per potassium in the sample are produced. During stage II gasification proceeds catalytically at a much reduced rate with the production of one CO molecule per equivalent H, molecule. The absence of CO or CO, evolution during stage I indicates the formation of a stable oxygen containing compound. This compound may be decomposed thermally by heating the sample up to 13OOK. CO evolves almost exclusively during this high temperature treatment. These results suggest a step reaction mechanism involving (I) the dissociative adsorption of water forming C-H and C-OH (phenol) groups.
(2) the formation of a K-0-c entity (phenolate), from the reaction of KOH with the phenol groups, (3) the d~omposition of these K-O-C entities to give CO, K,O and perhaps metallic potassium and (4) the formation of KOH from reaction of K,O with water. The transition from stage I to stage II is due to the consumotion of KOH to form K-Q-C snecies. The rate of the catalytic reaction (stage II) is controlled by the slokest step (3).