Study on Fe-P-O based Catalysts in the Gas\|phase Direct Oxidation of Benzene to Phenol with N_2O as an Oxidant

FePO\-4, FePO\-4/SiO\-2 (5%), Fe\-\{0.5\}Al\-\{0.5\}PO\-4 catalysts have been prepared and investigated for the gas\|phase direct oxidation of benzene to phenol with N2O as an oxidant. The conversion of benzene over FePO\-4 was 2%, and the selectivity to phenol was 85%; the conversion of benzene over FePO\-4/SiO\-2 (5%) was 7%, and the selectivity to phenol was 89%. Over Fe\-\{0.5\}Al\-\{0.5\}PO\-4, the reaction temperature could be decreased 100 ℃, and at 350 ℃ the conversion of benzene was 3.5%, and the selectivity to phenol was 60%. Characterization results showed that the tetrahedral coordinated FeO\-4 would play an important role during the reaction.