Catalytic decomposition of isopropanol over chromite spinels MCr2O4(M = Ni, Mn and Mg)
Abstract
The decomposition of isopropanol over nickel, manganese and magnesium chromite spinel catalysts has been investigated in the vapour phase in an integral reactor. Its decomposition follows first-order kinetics. Kinetic and thermodynamic parameters have been calculated using the Arrhenius and Eyring equations. The activity pattern is found to be NiCr2O4 > MnCr2O4 > MgCr2O4. The chromite spinels have been characterised by X-ray studies, i.r. spectral analysis, conductivity and thermoelectric potential measurements. All three chromites were found to be p-type semiconductors in the temperature range 150–400 °C. Exclusive dehydrogenation is shown by NiCr2O4 and MnCr2O4, whereas MgCr2O4 functions as a dehydrogenation and dehydration catalyst. A linear correlation exists between the entropy of activation and the activation energy for electrical conduction for the chromite spinels studied.