A comparative study of iron phthalocyanine electrocatalysts supported on different nanocarbons for oxygen reduction reaction

Developing non-platinum electrocatalyst with high performance and durability is strongly desired for the next-generation low-cost fuel cells. Here, we present a facile and scalable preparation method for the hybrid electrocatalysts of iron phthalocyanine (FePc) and seven different nanocarbons including carbon black (Vulcan and Ketjen black), carbon nanotubes, and mesoporous carbons. All the FePc/nanocarbon catalysts exhibited a higher activity for oxygen reduction reaction (ORR) than that of the commercial Pt/C, and the highest half-wave potential (0.918 V vs. RHE) ever reported in the literature was obtained from the composite catalyst of FePc and Ketjen black. Furthermore, the amount of electrochemically active sites (the centered iron ion of FePc) and turnover frequency of ORR on FePc were found to be respectively responsible for the electrocatalytic activities and long-term durability of the FePc/nanocarbon catalysts for ORR. We fabricated a MEA using FePc-KCB, anion electrolyte membrane and Pt/C as cathode, electrolyte membrane, and anode, respectively, and its power density in anionic medium reached 108 mW cm−2, which is higher than that of the conventional Pt/C catalyst. Such obtained results are important for the design of non-Pt based high efficient and durable ORR and fuel cell catalysts. [Display omitted]