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

Abstract

Iron(II) phthalocyanine (FePc) deposited onto two different carbonaceous supports was synthesized through an unconventional pyrolysis‐free method. The obtained materials were studied 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) configuration. 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 (243±7) μW cm−2, which was 33 % higher than that of FePc supported on nitrogen‐doped carbon nanotubes (Fe‐CNT(N); 182±5 μW cm−2). 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.

Boosting Microbial Fuel Cell Performance by Combining with an External Supercapacitor: An Electrochemical Study

“…Carbonaceous‐based materials and transition metal‐containing catalysts have replaced platinum successfully. The addition of transition metals and especially Fe−N−C active sites has improved significantly the performance almost doubling the MFCs output …”

“…The addition of transition metals and especially FeÀ NÀ C active sites has improved significantly the performance almost doubling the MFCs output. [38][39] The main problem that still persists with MFCs is the low power produced that makes it difficult to use directly for practical applications. Therefore, MFCs are usually coupled with an energy storage system (e. g. supercapacitors and batteries) that accumulate the energy produced and delivers it when needed.…”

High‐Power Microbial Fuel Cells Based on a Carbon–Carbon Composite Air Cathode

“…Compared with these achievements, herein, the MFCs with the NCCN‐AC air cathode exhibit impressively high power performance and also a high current density corresponding to the maximum power density (Figure e). Especially, the cathodes based on CNTs could only produce a maximum power density of 245–670 mW m −2 , and the highest power density from N‐doped CNTs was 1600 mW m −2 in previous publication, which is still 19% lower than that of pure NCCN air cathode and 23% lower than that of NCCN‐AC air cathode.…”

“…On the one hand, the intrinsic activity can be improved by optimizing the electronic structure of carbon materials by tuning the graphitization degrees, surface functional groups, defects, doping, guest components, etc . For instance, nitrogen doping is widely demonstrated as an excellent strategy to improve the ORR activity of carbon nanomaterials with a high current density and an efficient four‐electron transfer pathway . An MFC with a N‐doped carbon nanotube (CNT) cathode can achieve a high power density of 1600 mW m −2 , ≈15% higher than that of Pt/C, and performed a better durability .…”

Metal‐Nitrogen‐doped Porous Carbons Derived from Metal‐Containing Ionic Liquids for Oxygen Reduction Reaction

“…[13,14] Among theseh eteroatoms, N, [15][16][17][18] S, [19,20] P [21] and transition metals (e.g. Fe, [16,22,23] Co, [24] Cu [25] )h ave shown positive effects on catalyzing ORR. In addition, more than one kind of heteroatom embedded in carbon skeleton can further boost ORR, because carbon, nitrogen and metal elements combine with each other and improvee lectrocatalytic activitys ynergistically.…”