Decoupling the Electronic and Steric Effects on All‐Organic Electrocatalysts for Direct Oxygen Evolution Reaction

Abstract Compared with electronic effect, the steric configuration in oxygen evolution reaction (OER) electrocatalysts is also of vital importance to the intermediate adsorption, especially in those all‐organic systems, yet usually overlooked and hardly to be manipulated. Herein, the electronic and steric dual effects on OER are investigated through the design of non‐coplanar all‐organic electrocatalysts with/without carbonyl (C═O) modification. The polyimide‐typed MEC‐5 with conjugated naphthalene units demonstrates a surprisingly higher activity than its C═O modified counterpart MEC‐5‐O for alkaline OER, which exhibits a low overpotential of 342 ± 3 mV at a high current density of 0.5 A cm ⁻² , and a total charge transfer amount of 8.64 × 10 ⁴ C cm ⁻² during 120 h continuous catalysis, being 1–2 orders of magnitude higher than reported state‐of‐the‐art metal‐free electrocatalysts. Combined theoretical and operando experimental studies reveal that beyond the electron‐withdrawing effect of C═O, the steric effect plays a dominant role in regulating the adsorption energy of *OH and *O with a none‐equal proportion, leading to distinct activities of the catalysts. This work sheds light on the significance of stereochemical structure in designing efficient all‐organic electrocatalysts.