Effect of iron precursors on oxygen reduction reaction activity of FeN/ZIF-8 catalysts

Abstract

ZIF-8 attracted more attention as the carbon support for oxygen reduction reaction catalyst due to its large specific surface area and regular pore structure in recent years. A series of FeN/ZIF-8 catalysts were prepared using ZIF-8, 1,10-phenanthroline as carbon and nitrogen precursor, as well as FeSO4·7H2O, FeAc, FeCl3·6H2O and FeC10H10 were used as different iron precursors, respectively. The influence of different iron precursors on the structure and oxygen reduction reaction(ORR) activities of FeN/ZIF-8 catalysts were investigated by X-ray diffraction, specific surface area and pore size distribution measurements, transmission electron microscope, thermogravimetric analysis, and linear sweep voltammetry. The results show that the catalyst prepared with FeSO4·7H2O as iron precursor has the initial potential of about 0.93 V, and the ORR is a four-electron process, which has better oxygen reduction catalytic activity. Moderate specific surface area and pore size distribution, good crystal structure and uniform particle dispersion, as well as the presence of Fe3C are the possible reasons of resulting in better ORR activity of FeN/ZIF-8 with FeSO4·7H2O as the iron precursor.

Keywords

• oxygen reduction reaction
• zif-8
• fen/zif-8 catalyst
• iron precursor
• catalytic activity