Catalytic performance of iron oxide loaded on electron-rich surfaces of carbon nitride

Abstract

Carbon nitride (CN) in CN encapsulated Ni/Al2O3 (denoted as CN/Ni/Al2O3) catalyst was evidenced previously as a material in electron-rich state and possessed H2-dissociative adsorption activity due to the electron doping effect from underlying nickel. In this report, iron oxide loaded on the CN/Ni/Al2O3 was synthesized and investigated by Fischer-Tropsch (F-T) synthesis to test the special effect of electron-rich support on the catalytic activity of iron oxide. The Fe/CN/Al2O3 and CN/Ni/Al2O3 samples were accordingly synthesized for comparison. In Fe/CN/Ni/Al2O3, the iron oxide was reduced to magnetite by syngas as evidenced by the in-situ XPS measurements and XRD pattern of used catalyst. Compared with Fe/CN/Al2O3, more light hydrocarbons over Fe/CN/Ni/Al2O3 were observed. It should be understood by the interaction between iron oxide and support mainly due to the effect of electron-rich state and thus enhanced H2 adsorption ability. In addition, such a novel support facilitated the CO conversion and retarded the water-gas shift reaction and CO2 formation. The new type of adjustment on electronic state should be useful for novel catalyst design.