Iron and nitrogen doped carbon derived from ferrocene and ZIF-8 as proton exchange membrane fuel cell cathode catalyst

Abstract H2-O2 proton exchange membrane fuel cells (PEMFCs), one of the applications of hydrogen energy with specific energy density of 143 MJ/kg, might be a promising alternative to replace the use of fossil energy. The key to accelerate the application of PEMFCs is to design an efficient non-precious metal catalyst to lower the overpotential of the cathode oxygen reduction reaction (ORR). Herein, we developed a novel iron and nitrogen doped carbon (FeNC) catalyst using ferrocene as iron source, ZIF-8 as organic framework as well as the main carbon source. The regular morphology of ZIF-8 and ferrocene can prevent active sites from agglomeration, resulting a homogenous distribution of Fe, N and C. Moreover, the high specific area, porous structure and abundant catalytic Fe and N species gave rise to the ORR performance of the catalyst. As a result, the as-prepared FeNC catalyst showed an onset and half-wave potential of 0.95 V and 0.78 V in 0.1 M HClO4 with 1600 rpm, respectively. The catalysts were also applied in a PEMFC as the cathode catalysts with an open circuit voltage of more than 0.9 V and a maximum power density of 601 mW/cm2. Additionally, the as-prepared FeNC-1:30 catalyst showed a current density of 380 mA/cm2 at 0.7 V, which outperformed other as-prepared catalysts.