Zinc Oxide Catalysts

Abstract

Surface area and acetylene adsorptive ability of various zinc oxide catalysts of different make were measured. It was found that in adsorption of acetylene, Van der Waal's adsorption occurred at temperatures below 80°, and chiefly activated adsorption, accompanied with partial polymerization and decomposition, occurred at temperatures above 80°C. The physical adsorption of acetylene was found to be the maximum in a catalyst prepared by the pyrolysis of basic zinc carbonate precipitated with sodium carbonate. The same results were obtained with the surface area of the catalyst. Activated adsorption was the greatest in a catalyst prepared by the use of ammonium carbonate as the precipitant of basic zinc carbonate. As for the effect of sodium as an impurity and the temperature of heating, sodium was found to reduce both the amount of activated adsorption of acetylene and surface area of the catalyst. The surface area and acetylene adsorption were also found to be markedly decreased by heating zinc oxide to 500°C.