Promoting Oxygen Reduction Reaction by Inducing Out‐of‐Plane Polarization in a Metal Phthalocyanine Catalyst

Abstract

Abstract Metal phthalocyanine (MPc) material with a well‐defined MN 4 moiety offers a platform for catalyzing the oxygen reduction reaction (ORR), while the practical performance is often limited by the insufficient O 2 adsorption due to the planar MN 4 configuration. Here, a design (called Gr‐M G ‐O‐M P Pc) is proposed, where the metal of MPc (M P ) is axially coordinated to a single metal atom in graphene (Gr‐M G ) through a bridge‐bonded oxygen atom (O), introducing effective out‐of‐plane polarization to promote O 2 adsorption on MPc. Manipulating the out‐of‐plane polarization charge by varying types of M P and M G (M P = Fe/Co/Ni, M G = Ti/V/Cr/Mn/Fe/Co/Ni) in the axial coordination zone of ‐M G ‐O‐M P ‐ are examined by density functional theory simulations. Among them, the catalyst of Gr‐V‐O‐FePc stands out with the highest calculated O 2 adsorption energy, which is synthesized successfully and verified by systemic X‐ray absorption spectroscopy measurements. Importantly, it delivers a remarkable ORR performance with half‐wave potential of 0.925 V (versus reversible hydrogen electrode) and kinetic current density of 26.7 mA cm −2 . This thus demonstrates a new and simple way to pursue high catalytic performance by inducing out‐of‐plane polarization in catalysts.