Metal‐Free Chlorine Evolution via Nitrogen‐Rich Shell Modulation of Oxygen Active Sites in Hollow Mesoporous Carbon

ABSTRACT Electrocatalytic chlorine evolution reaction (CER) plays a critical role in chlorine production and chemical manufacturing, yet suffers from sluggish kinetics and poor selectivity under complex electrolyte conditions. Herein, a rationally designed electrocatalyst composed of a radially graded hollow carbon architecture in which oxygen‐rich mesoporous hollow carbon (MHC) is conformally coated with a nitrogen (N)‐enriched porous carbon shell (denoted D‐N@MHC) is reported. The outer N‐enriched shell electronically couples to the oxygen‐rich inner framework, regulating the electronic structure of oxygen active sites and thereby moderating Cl* adsorption toward the Sabatier optimum. The tailored interfacial electronic structure and local coordination environment of oxygen active sites promote chloride adsorption and accelerate reaction kinetics. As a result, D‐N@MHC delivers an ultralow overpotential of 80 mV at 10 mA cm −2 with 97.1% selectivity to Cl 2 , surpassing commercial noble‐metal catalysts and representing a benchmark of the reported carbon materials. Theoretical calculations further confirm the synergistic effect between active sites and interfacial regulation. Outer N‐enriched porous carbon shells on hollow carbon provide an effective strategy for constructing efficient durable and metal‐free CER anodes under harsh electrolytic conditions.