Study of supported copper chloride catalysts by electron paramagnetic resonance and X-ray diffraction

Abstract

Variations of catalytic properties of CuCl 2 supported on γ-alumina with active phase content and carrier thermal treatment were investigated by EPR and X-ray diffraction techniques. Two series of catalysts were prepared using γ-alumina, treated at 400 and 800 °C, as supports. In both series the copper content ranged from 0.3 to 8 wt % of the total catalyst weight. On the basis of EPR and X-ray diffraction studies, two different types of bonds between the oxygen of the γ-alumina surface and the copper ions are considered predominant in each series of catalysts. Catalyst activity and selectivity in the oxychlorination of benzene are discussed in terms of the chemical nature of these bonds and of the location of the copper chloride on the carrier surface.