Oxidation of cyclohexane with tert-butylhydroperoxide and hydrogen peroxide catalyzed by nano-sized γ-alumina supported metallophthalocyanines

In this study, nano-γ-alumina-supported unsubstituted Fe-, Co- and Mn-phthalocyanines were prepared and characterized. Catalytic activities of the supported phthalocyanines for the oxidation of cyclohexane with tert-butylhydroperoxide (TBHP) and H2O2 as the oxidant in the liquid phase were considered. For the MPc/nano-γ-alumina catalysts, a dimethylformamide:dichloromethane (3:7) solvent mixture was employed. The products of the catalytic reaction are cyclohexanone and cyclohexanol. The conversion percent of cyclohexane depended on the oxidant and the catalyst. TBHP was found to be a better oxidant than H2O2 since minimal destruction of the catalyst and higher conversion of cyclohexane were observed when this oxidant was employed. Under these reaction conditions, the order of catalytic activities is as follows: CoPc/γ-alumina > FePc/γ-alumina > MnPc/γ-alumina. Over γ-alumina, the conversion was much lower than on supported catalysts. The highest conversion of cyclohexane (13.21%) was observed on 10% CoPc supported.