Asymmetric Coordination Engineering of Conjugated Coordination Polymer Electrocatalysts for Acidic Oxygen Evolution

Designing efficient and stable iridium (Ir) single‐atom catalysts toward acidic oxygen evolution reaction (OER) is highly desired yet remains challenging, which faces significant limitations due to the support material design that fails to deliver satisfactory activity and durability under the harsh operating conditions of acidic OER. In this work, we develop high‐performance acidic OER catalysts with single‐atom Ir immobilized on polyimide material, featuring with well‐defined and asymmetric Ir‐N 2 O 2 coordination structures, which exhibits a low overpotential of 198 mV at 10 mA cm −2 with no activity decay for 500 h of operation. Through readily adjusting the molecular structure of polyimide support, two analogous catalysts with Ir‐N 2 O 2 and Ir‐C 2 O 2 coordination structures were investigated for a proof‐of‐concept study. Both the experimental and theoretical studies unravel that, relative to the Ir‐C 2 O 2 site, the Ir‐N 2 O 2 site with a higher Ir 5d state can significantly decrease the thermodynamic barrier for * OOH adsorption at the rate‐determining step. Moreover, the Ir‐N 2 O 2 site presents faster proton‐electron‐transfer kinetics arising from its appreciably promoted charge delocalization and enhanced proton concentration in the local chemical environment. This study highlights asymmetric coordination engineering as a promising approach toward catalytic performance enhancement of SACs in widespread energy‐conversion technologies.