The effect of specific catalysts on the reactions of the steam-carbon system

The reactions of the steam-carbon system have been studied by the static method at 750° C using extracted coconut charcoal to which iron, sodium, calcium and aluminium were added separately. The steam-carbon reaction is catalyzed chiefly by sodium, the carbon dioxide-carbon reaction by iron and sodium, while the heterogeneous oxidation of carbon monoxide by steam is enhanced by all the additions except aluminium. As required by the electronic theory of catalysis, the general course of the gasification of the carbon is found to be unaltered. Side reactions of the gases with the additions tend, however, to obscure changes in the rates of the individual steps, but give useful information about the composition of the catalysts under working conditions. The question of how the catalysts for the oxidation of carbon fulfil the role assigned to them by the electronic theory is discussed in the light of these results. An explanation is suggested in terms of the probable non-stoichiometric character of the atomic layers in closest contact with the carbon.