Spatial Isolation of Zeolitic Imidazole Frameworks‐Derived Cobalt Catalysts: From Nanoparticle, Atomic Cluster to Single Atom

The size effect of transition metal nanoparticles on electrocatalytic performance remains ambiguous especially when decreasing the size to atomic level. Herein, we report the spatial isolation of cobalt species at atomic scale through tuning zinc dopants content in predesigned bimetallic Zn/Co zeolitic imidazole frameworks (ZnCo‐ZIFs), affording the successful synthesis of nanoparticles, atomic clusters and single atoms of Co catalysts on N‐doped porous carbon. This novel synthetic strategy allows the investigation of size effect on electrochemical behaviours from nanometer to angstrom. Electrochemical results demonstrate that the single Co atomic catalyst manifests superior bifunctional ORR/OER activity, durability and reversibility for Zn‐air batteries in comparison with other counterparts and noble metal Pt/C+RuO2, which can be attributed to the isolated single Co atoms with high reactivity and stability. Our findings open up a new avenue to regulate the metal particle size and catalytic performance of metal‐organic framework derivatives at multiscale level.

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