Application of Measurements of Semi-conductivity to Heterogeneous Reactions

Abstract

IN the present investigation pure oxide films are obtained by the oxidation of evaporated metal films. Normal high-vacuum precautions are observed in the use of all-glass, greaseless systems with precise temperature control. The method of investigation Which has been developed is based on the semi-conducting properties of these oxide films. Simultaneous pressure and resistivity measurements are made during the adsorption and desorption of various gases on the oxide films over a range of temperatures between 0° and 250° C. While variations in conductivity of bulk semi-conductors on exposure to air have been previously observed and reported (Anderson et al.), the effect has not previously been applied to the problem of catalysis. Preliminary investigations Which have been carried out on copper oxide films have demonstrated the efficiency in obtaining reproducibility of the film during periodic oxidation and reduction.