Promoting Oxygen Reduction Reaction by Inducing Out‐of‐Plane Polarization in a Metal Phthalocyanine Catalyst
Xiyu Li, Xingshun Wu, Yuan Zhao, Yunxiang Lin, Jiahui Zhao, Chuanqiang Wu, Hengjie Liu, Lei Shan, Yang Li, Li Song, Jun Jiang
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.