Chloride‐Driven Interfacial Confinement Facilitates Adaptive Directional Electron Transfer in Hypersaline Environments

ABSTRACT Chloride ions (Cl − ) are conventionally regarded as inhibitory species in hypersaline wastewater treatment, where they cause active‐site shielding, radical scavenging, and catalyst deactivation. Contrary to this established view, we demonstrate that Cl − can transform from a passive inhibitor into an active interfacial regulatory species. We show that rather than suppressing reactivity, Cl − can reconfigure the confined solid‐liquid interface to modulate charge‐transfer kinetics and facilitate mass transport, establishing a new catalytic pathway. Herein, we report a Cl − ‐driven directional coordination strategy that combines the Cl − species with the catalyst interface and oxidant to construct an adaptive electron transfer channel (AETC). Multi‐scale experiments, density functional theory (DFT) calculations, and molecular dynamics simulations reveal that the Cl − ‐driven coordination changes internal electronic interactions, modulates orbital hybridization with the oxidant, and adjusts the interfacial hydrogen‐bonding network. This AETC alleviates mass‐transfer constraints and suppresses catalytic deactivation, enabling accelerated degradation kinetics alongside long‐term stability. Overall, this work challenges the traditional perception of Cl − , demonstrating that Cl − can drive constructive interfacial functions in extreme ionic environments.