Decomposition of cyclohexanol on the spinel system CuCr2-xFexO4

The System CuCr2-xFexO4 has been studied with a view to correlate the catalytic behavior of spinels on the decomposition of cyclohexanol. All the compositions between 0.0 less than or equal to x less than or equal to 1.0 had cubic symmetry and p-type semiconductivity except the compound CuCr2O4 (x=0.0) which showed tetragonal symmetry. The activation energy for the electronic conduction varied between 0.38 and 0.13 eV. The Seebeck coefficient (alpha) was found to increase with increases in 'x'. Catalytic evaluation was done in the temperature range 200-400 degrees C using cyclohexanol as a probe molecule. Our results show CuCrFeO4 to be a better catalyst for cyclohexanol decomposition than CuCr2O4. The percent decomposition of alcohol increased with increases in mobility of charge carriers and decreases in values of activation energy. Further, dehydrogenation selectivity increased with increases in p-type behavior of the compositions from CuCr2O4 to CuCrFeO4. X-ray and IR studies indicated that the spinel catalysts are quite stable over the temperature range investigated.