Coupling Ni Single Atomic Sites with Metallic Aggregates at Adjacent Geometry on Carbon Support for Efficient...

Single atomic catalysts have shown great potential in efficiently electro-converting O₂ to H₂O₂ with high selectivity. However, the impact of coordination environment and introduction of extra metallic aggregates on catalytic performance still remains unclear. Herein, first a series of carbon-based catalysts with embedded coupling Ni single atomic sites and corresponding metallic nanoparticles at adjacent geometry is synthesized. Careful performance evaluation reveals Ni_SA/Ni_NP-NSCNT catalyst with precisely controlled active centers of synergetic adjacent Ni-N₄S single sites and crystalline Ni nanoparticles exhibits a high H₂O₂ selectivity over 92.7% within a wide potential range (maximum selectivity can reach 98.4%). Theoretical studies uncover that spatially coupling single atomic NiN₄S sites with metallic Ni aggregates in close proximity can optimize the adsorption behavior of key intermediates ^*OOH to achieve a nearly ideal binding strength, which thus affording a kinetically favorable pathway for H₂O₂ production. This strategy of manipulating the interaction between single atoms and metallic aggregates offers a promising direction to design new high-performance catalysts for practical H₂O₂ electrosynthesis.