Conjugated Coordination Polymer Aerogels with Unsaturated Single-Atom Metal Sites for Efficient Neutral Oxygen Evolution

Abstract

Designing high-performance single-atom catalysts with a precisely designed configuration is important in extensive energy-conversion technologies, which presents enormous potentials to be extensively applied. Defect-enriched conjugated coordination polymer aerogels (d-CCPAs) with abundant coordinatively unsaturated single-atom metal sites and the counterpart conjugated coordination polymer aerogel were developed, with Ni1–O2 and Ni1–O4 motifs employed as model systems for comparative investigation. Our findings reveal that the Ni1–O2 sites with elevated Ni d-band centers lower the thermodynamic barrier for the neutral OER, while the defective structure of d-CCPA accelerates reactant transport and improves active-site accessibility. Consequently, the d-CCPA delivers an ultralow overpotential of 213 mV at 10 mA/cm2 and maintains good durability over 400 h. Such d-CCPA catalysts feature exceptional tunability of active sites given the diversities of metal precursors and organic ligands, holding immense potential for application in widespread catalytic reactions.