Dynamic Heterovalent Dual‐Cu Sites for O═O Cleavage in Electrocatalytic Oxygen Reduction Reaction

Activation and cleavage of the inert O═O bond represent a central challenge in energy electrochemistry. Here, the Cu dual‐atom catalyst (Cu‐DAC) is constructed via bottom‐up pre‐coordination assembly and post‐encapsulation pyrolysis. The resulting Cu‐DAC features a well‐defined Cu–Cu distance (∼3.31 Å) with switchable Cu 1+ /Cu 2+ states, enabling dynamic dual‐site coordination with O 2 . Cu‐DAC achieves 0.87 V RHE half‐wave potential for oxygen reduction reaction (ORR), a near‐unity 4e − selectivity, and outstanding stability. Multiple operando spectroscopic characterizations and ab initio dynamic simulations (AIMD) reveal that the dynamic heterovalent [Cu 1+─ O─O · − ─Cu 2+ ] unit elongates the O–O bond and promotes its cleavage via dual‐site confinement and electron donation. By specifically elucidating how these dual‐atom sites dynamically evolve to facilitate O─O bond cleavage, we provide vital atomic‐level principles for the rational design of dynamically active catalysts.