Electron‐Deficient Linkers Enhance H 2 O 2 Electrosynthesis in Covalent Organic Frameworks

ABSTRACT Electrocatalytic hydrogen peroxide (H 2 O 2 ) production through the two‐electron oxygen reduction reaction (2e − ORR) offers a promising route for sustainable H 2 O 2 synthesis under ambient conditions. However, the development of electrocatalysts that simultaneously exhibit high activity, selectivity, and stability remains challenging. Specifically, achieving precise control over catalytic centers remains challenging. Herein, an electron‐deficient linker engineering approach based on π‐conjugation tuning is proposed to tailor the electronic structure of nickel phthalocyanine (Ni−N 4 ) active sites in covalent organic frameworks (COFs). Three dianhydride derivatives (i.e., benzene‐1,2,4,5‐tetracarboxylic dianhydride (PMDA), 1,4,5,8‐naphthalenetetracarboxylic dianhydride (NTDA), and perylene‐3,4,9,10‐tetracarboxylic dianhydride (PTDA)) were utilized to synthesize NiPc‐PMDA, NiPc‐NTDA, and NiPc‐PTDA COFs. Benefiting from the π‐conjugation‐tuned linker electronic properties, NiPc‐PTDA demonstrates an outstanding 2e − ORR selectivity of 92% and a high H 2 O 2 production rate of 34.8 mol g cat −1 h −1 in a two‐electrode flow cell. Combined theoretical and experimental results support a correlation between linker electronic properties, the electronic state of the Ni centers, Ni–*OOH interaction, and the thermodynamic branching between H 2 O 2 release and further *OOH reduction. This work highlights the role of linker electronic properties in regulating catalytic centers and provides a π‐conjugation‐guided linker‐design approach for selective H 2 O 2 electrosynthesis in NiPc‐based COFs.