Abstract
Single atomic catalysts have shown great potential in efficiently electro-converting O(2) to H(2)O(2) 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-N(4)S single sites and crystalline Ni nanoparticles exhibits a high H(2)O(2) selectivity over 92.7% within a wide potential range (maximum selectivity can reach 98.4%). Theoretical studies uncover that spatially coupling single atomic NiN(4)S 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 H(2)O(2) 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 H(2)O(2) electrosynthesis.