Nonstoichiometric Copper Bismuth Oxide Catalyst Boosting Surface‐Bound Cu(III)‐Peroxo Intermediate for Selective Oxidation via Dark Peroxydisulfate Activation

While high‐valent copper intermediates are pivotal for efficient peroxydisulfate (PDS) activation, their generation and role in heterogeneous catalysis remain unclear. Herein, we demonstrate that a nonstoichiometric Cu 0.84 Bi 2.08 O 4 catalyst enables the dark activation of PDS via a novel pathway dominated by a surface‐bound Cu(III)‐peroxo intermediate ( ≡ Cu(III)‐O−O−SO 3 ). A suite of spectroscopic and chemical probes revealed that this Cu(III)‐peroxo species, along with superoxide radicals (•O 2 − ), acts as the primary oxidant, enabling the highly selective and rapid degradation of bisphenol A (BPA) and other phenolic pollutants. Furthermore, H 2 O 2 generated from PDS hydrolysis synergistically participates in the reaction, accounting for the exceptionally high PDS utilization efficiency of the system. The system exhibits remarkable robustness, maintaining high activity over a wide pH range (4–11) and demonstrating strong resistance to interference from ions. This study elucidates a distinct Cu(III)‐peroxo‐mediated mechanism and offers a new strategy for designing highly selective catalysts for environmental remediation.