3335. TAYLOR, H. S., AND BURNS, R. M. Adsorption of Gases by Metallic Catalysts. Jour. Am. Chem. Soc., vol. 43, 1921, pp. 1273-1287; Chem. Abs., vol. 15, 1921, p. 3922. Measurements of the adsorption of H2, CO, and CO2 and C2H4 by finely divided Ni, Co, Fe, Cu, Pd, and Pt were made. Adsorption by a metallic catalyst is not like adsorption by such inert substances as charcoal and silica gels. It is specific, and saturation capacity is reached at low partial pressures of the gas. It is a surface phenomenon involving electronic rearrangements in both catalyst and adsorbed gas. Methods of preparation, which produce good metallic catalysts also produce metals with high powers of adsorption for gases whose reaction they catalyze, but the temperature of maximum adsorption is often lower than temperature of maximum chemical activity. This probably means that a free evaporation of both reactants and resultants is necessary for rapid chemical action. The greater the adsorption the lower is the temperature at which catalytic action begins. |