Tailoring Oxygen‐Bridged Ru─Ti Asymmetric Pairs Enables Low‐Overpotential Two‐Electron Water Oxidation

ABSTRACT Electrochemical two‐electron water oxidation (2e‐WOR) offers a promising direct route to on‐site hydrogen peroxide (H 2 O 2 ) production, yet state‐of‐the‐art catalysts still suffer from intrinsically low selectivity and large overpotentials, especially in near‐neutral media. Equally unresolved is how the electrolyte composition steers the competition between 2e‐WOR and the thermodynamically favored four‐electron oxygen evolution reaction (OER). Here we employed a monolayer TiO 2 nanosheet platform to anchor atomically dispersed 3d/4d transition‐metal centers (Ru 1 , Cu 1 , Co 1 , and Fe 1 ). Among them, Ru 1 ‐TiO 2 delivers an optimal Faradaic efficiency (FE) of 60.8% at a low overpotential of 130 mV. Further analysis reveals that the oxygen‐bridged Ru─Ti (Ru─O─Ti) asymmetric dimer establishes a gradient d‐p‐d orbital coupling. This electronic motif strengthens the adsorption of HCO 3 * while attenuating the over‐binding of OH*, thereby switching the surface termination from OH* to HCO 3 *‐rich. Consequently, a bicarbonate‐mediated 2e‐WOR pathway is selectively activated over the Ru─O─Ti sites, which is much more favorable than the conventional OH*‐OH* coupling route. These findings underscore that gradient orbital coupling across asymmetric atomic pairs act as an electronic lever to redirect the catalytic trajectory, furnishing a general principle for pathway control in diverse electrosynthesis systems.