Effect of Li2O-doping of nanocrystalline CoO/Fe2O3 on isopropanol conversion

The catalytic conversion of isopropanol was carried out over pure and Li2O-doped (0.75–4.5 mol%) cobalt ferrite prepared by heating Fe/Co mixed hydroxides at 400 and 600 °C. The techniques employed were XRD, N2 adsorption at −196 °C and conversion of isopropanol at 200–400 °C using a flow method. The results showed that Li2O-doping and increasing the heating temperature of the system investigated from 400 to 600 °C stimulated CoFe2O4 formation also. Pure and variously doped solids were moderately crystallized CoFe2O4 phase having a crystallite size varying between 5 and 15 nm. The SBET of various solids was found to decrease by increasing their calcination temperature and also by doping with 4.5 mol% Li2O. However, this treatment, resulted in a significant increase in their catalytic activities which much increased by doping. The presence of 1.5 mol% Li2O brought about an increase in the catalytic activity, measured at 300 °C, of 97% and 63% for the solids being calcined at 400 and 600 °C, respectively. All solids investigated behaved as dehydrogenation catalysts (having selectivities to acetone formation above 95%). The doping process did not alter the mechanism of dehydrogenation of isopropanol, but increased the concentration of active sites involved in the catalyzed reaction.