Fe-N-C Oxygen Reduction Catalysts Supported on Burned-off Activated Carbon

Fe-N-C catalysts were prepared by impregnating FeCl3 within two kinds of activated carbon (Kuraray GC and Nuchar) that had been previously burned-off at 500 degrees C in air to vary their pore sizes in a controlled way. The impregnated samples were subsequently heated at 850 degrees C in NH3. The average pore size of the samples was determined by small-angle X-Ray scattering (SAXS) measurements and quantified by the radius of gyration (R-g) of the pores. The catalytic activities of the samples vary with the pore size of the activated carbon, which depends on the bum-off time. The results support suggestions from the Dodelet group about the importance of the pore size in determining catalytic activity.