The kinetics of oxidation and hydrogenation of ground charcoal in the presence of nickel, cobalt, and molybdenum catalysts have been studied using a microbalance and in situ X-ray diffraction to identify the phases present during the reactions. Nickel and cobalt were found to be better catalysts than molybdenum for the oxidation of carbon. However, addition of molybdenum to the other metals resulted in increased catalytic activity, probably because of decreased crystal growth or sintering of the active phases. The promoting effect of molybdenum was less clear in the case of carbon hydrogenation, which took place in two distinct temperature ranges (between 773 and 973 K and above 1023 K) with nickel catalysts. Possible mechanisms of the catalyzed reactions are discussed.