Spin Manipulation of Heterogeneous Molecular Electrocatalysts by an Integrated Magnetic Field for Efficient Oxygen Redox Reactions

Abstract Understanding the spin‐dependent activity of nitrogen‐coordinated single metal atom (M‐N‐C) electrocatalysts for oxygen reduction and evolution reactions (ORR and OER) remains challenging due to the lack of structure‐defined catalysts and effective spin manipulation tools. Herein, both challenges using a magnetic field integrated heterogeneous molecular electrocatalyst prepared by anchoring cobalt phthalocyanine (CoPc) deposited carbon black on polymer‐protected magnet nanoparticles, are addressed. The built‐in magnetic field can shift the Co center from low‐ to high‐spin (HS) state without atomic structure modification, affording one‐order higher turnover frequency, a 50% increased H 2 O 2 selectivity for ORR, and a ≈4000% magnetocurrent enhancement for OER. This catalyst can significantly minimize magnet usage, enabling safe and continuous production of a pure H 2 O 2 solution for 100 h from a 100 cm 2 electrolyzer. The new strategy demonstrated here also applies to other metal phthalocyanine‐based catalysts, offering a universal platform for studying spin‐related electrochemical processes.