MOF-Derived Cobalt Nanoparticles with Dispersed Iron Phthalocyanines as Bifunctional Oxygen Electrocatalysts

Abstract

Iron phthalocyanine (FePc), characterized by its distinctive Fe−N 4 sites, represents a macromolecular catalyst with promising applications in bifunctional oxygen catalysis. However, its inherently flat and symmetrical configuration often results in relatively weak electrocatalytic performance. In this study, a novel approach was employed by first anchoring the Co-based zeolitic imidazolate framework onto microsized carbon spheres derived from a Zn-based coordination polymer, followed by the incorporation of dispersed FePc molecules. The resultant catalyst, denoted as FePc-CoNC-CMS, exhibited remarkable bifunctional oxygen reduction reaction/oxygen evolution reaction (ORR/OER) activity in an alkaline medium, notably achieving a half-wave potential of 0.87 V and an overpotential of 313 mV at 10 mA cm −2 . Both experimental and theoretical investigations revealed that the presence of FePc on the cobalt surface induced significant alterations in the electron distribution within the Fe center, thereby regulating the adsorption affinity of Fe−N 4 sites toward oxygen. This structural modification led to outstanding bifunctional activity. When applied in zinc−air batteries, it demonstrated an excellent power density of 147.6 mW cm −2 and satisfactory charge−discharge stability over a period of 70 h at 10 mA cm −2 . This pioneering work integrates metal−organic framework-derived metal−carbon nanomaterials with macromolecular catalysts, offering a novel and efficient pathway for multifunctional applications.