ROLE OF CDO/CD-2+ CONTENT ON THE ELECTRICAL-CONDUCTIVITY AND CATALYTIC BEHAVIOR OF CO1.0-X-CDX-FE2.0 OXIDE SPINEL SYSTEM (0.0-LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-0.5) FOR THE DECOMPOSITION OF 2 PROPANOL

A series of Co1.0-x-Cdx-Fe2.0 oxides as well as their corresponding spinels (x = 0.0, 0.1, 0.3 and 0.5) were prepared. Calcination was conducted between 500 and 1000-degrees-C. X-ray diffraction and IR spectral studies were used to identify the different phases present. Conductance properties of these samples were studied using electrical conductance measurements between 100 and 400-degrees-C. An increase in cadmium content of the sample decreases the conduction activation energy (E-sigma) in the order: 0.0 > 0.1 > 0.3 > 0.5. The highest E-sigma values were observed for the 600-degrees-C samples. The variation of the E values were discussed in terms of the oxides' semiconducting properties and the ion concentration in the octahedral-tetrahedral sites of the spinel structure. The catalytic decomposition of 2 propanol was carried out in the temperature range 250-400-degrees-C, using a flow system. Co1.0Fe2.004 spinel selectively catalyses the dehydrogenation of 2 propanol between 275 and 350-degrees-C. Maximum activity was observed for the 600-degrees-C sample. The activity towards acetone formation decreases in the order: 0.1 > 0.3 > 0.0 > 0.5. Correlations were attempted between catalyst composition and their catalytic activity. The mechanism is discussed in terms of surface isopropanolate intermediate formation.