Phthalocyanine tethered iron phthalocyanine on graphitized carbon black as superior electrocatalyst for oxygen reduction reaction

Despite the superior electrocatalytic activity of iron (II) phthalocyanine (FePc) for oxygen reduction reaction (ORR) in alkaline media, the large-scale applications of these FePc-based materials are still greatly hindered by their rapidly declined activity. To overcome this obstacle, it is essential to enhance the catalytic durability of FePc-based electrocatalysts. Herein, we demonstrate a superior FePc-based catalyst by employing low-cost graphitized carbon black as carbon supports, and tuning the Fe coordination environment in FePc, via the delocalized π coordination. Owing to the excellent ORR catalytic activity (the specific activity of 2.26 mA cm−2, 3.6-fold enhancements compared with the commercial Pt/C catalyst), the remarkable durability (after 3000 potential cycles, 3-mV shifts for the half-wave potential, only 4.2% decreases from the initial specific activity) and the outstanding selectivity (good methanol tolerance, and free from interfering species effects, including NO3-, SO42-, PO43-, Br-, Cl- and SCN-), the novel FePc-based electrocatalyst is promising substitutes for Pt-based catalysts for ORR. Furthermore, to better elucidate the origin of the ORR performance, the density functional theory (DFT) calculation indicates that the unique structure of phthalocyanine tethered iron phthalocyanine (Pc-FePc) plays a key role in improving of both the catalytic activity and durability.