Electronic Structure Regulation of Iron Phthalocyanine Induced by Anchoring on Heteroatom‐Doping Carbon Sphere for Efficient Oxygen Reduction Reaction and Al–Air Battery

Abstract

Aluminum–air batteries (AABs) are deemed as a potential clean energy storage device. However, exploiting high‐efficiency and stable oxygen reduction reaction (ORR) electrocatalysts in AABs is still a challenge. Iron phthalocyanine (FePc) shows a great prospect in ORR but still far from Pt‐based catalysts. Here, the hybrid electrocatalysts of monolayer FePc and hollow N,S‐doped carbon spheres (HNSCs) are innovatively constructed through π–π stacking to achieve high dispersion. The resulting FePc@HNSC catalyst exhibits an outstanding ORR activity, outperforming that of pristine FePc and even most Fe‐based catalysts reported to date. Moreover, the AAB using FePc@HNSC catalyst not only demonstrates a superior power density than the battery with Pt/C, but also displays stable discharge voltages and excellent durability. Furthermore, the theoretical calculations confirm that the charge distribution and d‐band center of the Fe atom in FePc are efficiently optimized by hybrid configuration via the introduction of N,S‐doped carbon substrate. The design leads to an enriched electron density around Fe active sites and significant reduction of energy barrier for OH* formation, which are favorable for the improvement of electrocatalytic ORR performance. This work provides a chance to expand the application of metallic macrocyclic compound electrocatalysts in various energy technologies.

Construction of a Co/MnO Mott–Schottky Heterostructure to Achieve Interfacial Synergy in the Oxygen Reduction Reaction for Aluminum–Air Batteries

“…3−5 However, the development of Al−air batteries is greatly limited by the sluggish kinetics of the oxygen reduction reaction (ORR) on the air cathode, and this limitation can be overcome by the rational design of ORR electrocatalysts. 6,7 In decades, various kinds of low-cost ORR catalysts including carbon materials, transitional metal alloy/compound, and conductive frameworks have been developed. 8 Gong et al designed vertically aligned nitrogen-containing carbon nanotubes with high ORR catalytic activity, 9 inspiring the development of doped carbon catalysts for ORR in 2009.…”

Regulation of the B Site at La(Ni0.1)MnO3 Perovskite Decorated with N-Doped Carbon for a Bifunctional Electrocatalyst in Zn–Air Batteries

“…To solve the issues of diminishing fossil fuels and deteriorating the environment, tremendous efforts have been devoted to exploring clean energy sources and energy conversion/storage devices to achieve the low-carbon energy transition. , More recently, metal–air batteries have been principally used as energy conversion systems owing to safety and high theoretic energy densities . Among these, zinc–air batteries (ZABs) have received particular attention due to high theoretical specific energy density, abundant reserves of zinc, almost unlimited oxygen supply, environmental friendliness, and safe operation .…”

“…1,2 More recently, metal−air batteries have been principally used as energy conversion systems owing to safety and high theoretic energy densities. 3 Among these, zinc−air batteries (ZABs) have received particular attention due to high theoretical specific energy density, abundant reserves of zinc, almost unlimited oxygen supply, environmental friendliness, and safe operation. 4 However, their commercialization has been limited by the sluggish reaction kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) occurring at air electrodes.…”

Electrocatalytic Performance of Fe–N Encapsulated in Hollowly Mesoporous Carbon Microspheres for Oxygen Reduction Reaction and Zn–Air Battery

“…For example, iron phthalocyanine (FePc) with a typical structure of a central Fe atom coordinated with four nitrogen ligands was anchored onto a carbon sphere or nanotubes to optimize its charge distribution, thus improving its ORR property. 18,19 However, the demetalation of molecular catalysts leads to a rapid decrease in activity; meanwhile, the inevitable Fenton reaction of Fe II ions in Fe II Pc results in instability of acidic electrolytes. 20 However, the coordinated Fe atoms of single-atom catalysts (SACs) are directly stabilized on a carbon support, thus effectively preventing the demetalation and facilitating electron transport.…”

“…Thus, metal-based ORR catalysts with molecular or single-atom active sites are widely developed. For example, iron phthalocyanine (FePc) with a typical structure of a central Fe atom coordinated with four nitrogen ligands was anchored onto a carbon sphere or nanotubes to optimize its charge distribution, thus improving its ORR property. , However, the demetalation of molecular catalysts leads to a rapid decrease in activity; meanwhile, the inevitable Fenton reaction of Fe II ions in Fe II Pc results in instability of acidic electrolytes …”