Dual-Atomic Catalysts Deduced from d−π Conjugated Metal−Organic Frameworks for Efficient Oxygen Evolution Reaction

A series of semiconductive cobalt-based metal–organic framework (MOFs) are prepared in this work using 2,3,6,7,10,11-hexaiminotriphenylene (HATP) as ligand and diverse metal ions as the second coordination centers (M = Mn, Ni, and Zn) (denoted as Co x M 3-x (HITP) 2 MOFs). The series of bimetallic Co x M 3-x (HITP) 2 MOFs exhibit ultrathin graphene-like nanostructure, highly d–π conjugated network, large specific surface areas, and diverse metal coordination modes. Density functional theory calculations reveal the unique synergism between M (M = Mn, Ni, and Zn) and Co nodes, in which adjacent layers of M atoms can efficiently modulate the electron densities of Co atoms in Co 3 (HITP) 2 . As compared, Co x Zn 3-x (HITP) 2 MOF possesses substantially enhanced electron density around the Co atoms, dual-metal atomic sites, and rich metal coordination modes, and exhibits superior electrochemical activity. Among them, Co x Zn 3-x (HITP) 2 displays the outperformed electrocatalytic performances of the oxygen evolution reaction (OER). Particularly, Co x Zn 3-x (HITP) 2 shows the lowest overpotential of 210 mV and good long-term stability. This work develops an efficient strategy for designing and regulating atomically dispersed catalysts in conductive MOFs toward clean energy applications.