Steering Pulsed Electrochemistry Selectivity Toward Singlet Oxygen via Dynamic Intermediate Management

The electrocatalytic generation of singlet oxygen (¹O₂) from molecular oxygen activation offers a green and selective route for water decontamination. However, its practical application is fundamentally constrained by the sluggish desorption of key ^*OOH intermediates, leading to a pervasive "selectivity-efficiency" trade-off. Herein, we design a pulse excitation electrocatalytic system based on a copper electrode featuring tailored nanotip architecture (Cu-T) that synergistically integrates spatial electric field enhancement with dynamic potential control. Under optimized pulsed operation, the system achieves exceptional ¹O₂ selectivity (>90%) and oxygen conversion efficiency (>73%), significantly outperforming conventional potentiostatic methods. In situ spectroscopic analyses and multiphysics simulations reveal that the pulsed protocol coupling with tip effect promotes O₂ adsorption, stabilizes key ^*OOH intermediates, and facilitates their recombination into ¹O₂, thereby bypassing the rate-limiting ^*OOH desorption step. The system also demonstrates broad applicability across diverse organic pollutants and complex water matrices, alongside robust stability in continuous-flow operation. This work establishes a general spatiotemporal strategy to steer electrocatalytic pathways toward highly selective and energy-efficient O₂ activation.