The synergism of cadmium on the catalytic activity of Cd–Cr–O system: I. Preparation, characterization and electrical properties

Abstract

Cadmium-containing catalysts were obtained by calcining a parent mixture of chromia and cadmium nitrate precursor materials in atomic ratio Cd/Cr=0.5. The thermal genesis of the catalysts was explored by means of thermogravimetric analysis (TGA) in different atmospheres (air, nitrogen, and hydrogen) and in the temperature range 25–1000°C. The calcination products were characterized by adopting many techniques such as differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), estimation of surface excess Cr6+ concentration, surface area, and electrical conductivity measurements. It was demonstrated that raising the calcination temperature of Cd/Cr mixture results in many effects on the structural as well as the electrical properties of the calcination products. The role of Cd2+ ions in improving the electrical behavior of such a mixture was discussed. The results of the present study offer the advantageously usage of Cd/Cr catalysts over the net chromia catalyst in the dehydration/dehydrogenation of alcohols as it will be discussed in the next paper.