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

Single atomic catalysts have shown great potential in efficiently electro-converting O to HO 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/Ni-NSCNT catalyst with precisely controlled active centers of synergetic adjacent Ni-NS single sites and crystalline Ni nanoparticles exhibits a high HO selectivity over 92.7% within a wide potential range (maximum selectivity can reach 98.4%). Theoretical studies uncover that spatially coupling single atomic NiNS 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 HO 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 HO electrosynthesis.