COBALT CATALYSTS SUPPORTED ON SILICA GEL STUDIED BY POSITRON ANNIHILATION

摘要

Positron lifetime and Doppler broadening measurements were carried out for cobalt catalysts supported on silica gel. The catalysts were prepared by impregnation with aqueous solutions of cobalt salts (acetate, nitrate and chloride) and subsequent hydrogen treatment at 450°C. Variation of positron annihilation parameters as a function of cobalt loading was found to depend strongly on the cobalt salt used for the catalyst preparation.