Bio-gel template synthesis of CoFe2O4 nano-catalysts and application in aerobic oxidation of cyclohexane

Abstract Magnetic cobalt ferrite (CoFe 2 O 4 ) particles were synthesized via a solvothermal pathway by using the gel of natural lotus roots as bio-gel template. Samples with porous structure and of large specific area (∼95.6 m 2 /g) were prepared, which were assembled by CoFe 2 O 4 particles of uniform sizes ( ca. 15.0 nm). The annealed CoFe 2 O 4 nanoparticles were proven to be highly efficient catalysts for aerobic oxidation of cyclohexane. Factors such as oxygen pressure, temperature, reaction time and self-catalysis by adding cyclohexanone have been studied in view of improving the conversion of cyclohexane as well as the selectivity of KA oil (cyclohexanone and cyclohexanol). Optimum parameters were found at an initial O 2 pressure of 1.6 MPa when the reaction was conducted for 6.0 h at the temperature of 150 °C. The maximum conversion of cyclohexane oxidation reaches 16.43%, and the selectivity 90.3% for KA oil was obtained. This research provides a facile way of developing green catalysts in the aerobic oxidation of cyclohexane.