An Insight into the Relation of Spin-Polarization and Oxygen Evolution Enhancement with a Monolayer Chiral Covalent Organic Framework Model Catalyst

Manipulating the electron spin state through the chiral-induced spin selectivity (CISS) effect provides a novel strategy for enhancing the activity and selectivity of the oxygen evolution reaction (OER). However, developing a quantitative relationship between the CISS effect and the chirality-enhanced OER performance is difficult due to complex influencing factors. Herein, using a ligand exchange strategy, we developed a monolayer chiral covalent organic framework (mc-COF) model catalytic system with adjustable spin polarization (P = ∼49–72%), which allows the decoupling of the CISS effect from other influencing factors on the OER performance. A supralinear dependence between the spin polarization and chirality-enhanced OER performance is established. This confirms that the chirality-enhanced electrocatalytic performance is significantly amplified by spin polarization due to the CISS effect. Moreover, in situ measurements reveal that the CISS effect of mc-COFs optimizes the reaction pathway by aligning *OH spins parallel, suppressing H2O2 formation, facilitating spin-oriented intermediates (*OOH and *OO) at lower potentials, and accelerating *OOH-to-*O–O conversion.