Design of Iron(II) Phthalocyanine-Derived Oxygen Reduction Electrocatalysts for High-Power-Density Microbial Fuel Cells

Iron(II) phthalocyanine (FePc) deposited onto two different car- bonaceous supports was synthesized through an unconven- tional pyrolysis-free method. The obtained materials were stud- ied in the oxygen reduction reaction (ORR) in neutral media through incorporation in an air-breathing cathode structure and tested in an operating microbial fuel cell (MFC) configura- tion. Rotating ring disk electrode (RRDE) analysis revealed high performances of the Fe-based catalysts compared with that of activated carbon (AC). The FePc supported on Black-Pearl carbon black [Fe-BP(N)] exhibits the highest performance in
terms of its more positive onset potential, positive shift of the half-wave potential, and higher limiting current as well as the highest power density in the operating MFC of (243ﰁ 7) mW cmﰃ2, which was 33 % higher than that of FePc support- ed on nitrogen-doped carbon nanotubes (Fe-CNT(N) ; 182 ﰁ 5 mW cmﰃ2). The power density generated by Fe-BP(N) was 92 % higher than that of the MFC utilizing AC ; therefore, the utilization of platinum group metal-free catalysts can boost the performances of MFCs significantly.