Interaction between the Active Components and Support in the Co-MO-Al,O, System III. Magnetic and Electron Spin Resonance Spectroscopic Study of the Influence of Sodium on the Nature of Cobalt

Abstract

The influence of sodium on the magnetic and electron spin resonance properties of Co-Mo- Al208 catalysts both in the fresh state and after reduction at various temperatures in hydrogen, hydrogen-isooctene and hydrogen-isooctene-thiophene atmospheres has been investigated. In samples containing sodium, metallic cobalt is formed on reduction in hydrogen or hydrogenisooctene at 500°C. In the presence of sulfur as well as in samples not containing sodium, reduction to the metal is suppressed. In addition to this influence on cobalt, sodium also enhances the reducibility of molybdenum ions in the support. These results lend additional support to the model of the catalyst surface proposed in part II of this series and highlight the importance of the alumina support in determining the structural characteristics of “cobalt-moly” catalysts.