Spontaneous Alkaline Water Electrolysis Driven by the “OH‐Baton”

Abstract Nano‐metal particles integrating with single‐atom catalysts (NMP‐SACs) have been constructed recently for accelerated alkaline hydrogen evolution reaction (HER). However, the design of NMP‐SACs primarily aims at the separate adsorption of *OH and H*, while neglecting the *OH desorption, causing *OH blockage and slow kinetics. To address this, Mo ₂ C is introduced to NMP‐SACs (e.g., Pt nanoparticles‐Pt atom, Pt _n ‐Pt ₁ ) by a “one‐step dual‐confinement pyrolysis” strategy for Pt _n ‐Pt _1@Mo2C , where Pt ₁ precisely confined by Mo ₂ C with Pt _n remaining adjacent to Pt ₁ @Mo ₂ C. Experiments and calculations demonstrate that Mo ₂ C acting as an “OH‐baton” helps overcome *OH blockage on Pt ₁ , accelerating the separation of H* and *OH and thus promoting spontaneous alkaline water dissociation. Thus, the supported Pt _n ‐Pt ₁ @Mo ₂ C achieves a significantly lower overpotential ( η ₁₀ = 24 mV) and a more than seven times higher mass activity (MA ₁₀₀ = 4.33 mA µg Pt⁻ ¹ ) than Pt _n ‐Pt ₁ in alkaline. The alkaline anion‐exchange membrane water electrolyzer (AEMWE) delivers a low cell voltage of 1.91 V and durable 120 h of electrolysis at 1.0 A cm ⁻² . This work proposes a new insight for introducing an “OH‐baton” in a dual‐site catalyst system to achieve spontaneous alkaline water dissociation.