Ru‐W 2 C Janus Schottky Junction Accelerating Alkaline Hydrogen Evolution via Dual‐Channel Hydrogen Supply

ABSTRACT Heterostructures can accelerate the alkaline hydrogen evolution reaction (HER) through the typical “dual‐site” mechanism, where one site is responsible for water cleavage while the other facilitates hydrogen generation. However, this dual‐site mechanism never fully exploits the interface functions due to interfacial disorder in conventional heterostructures, thereby hindering the full activation of the intrinsic catalytic activity. Herein, by constructing an ordered Ru‐W 2 C Janus Schottky junction, we overcome the constraint of the typical dual‐site mechanism and facilitate the full activation of the Schottky junction. Experiments and calculations reveal a distinct reaction pathway in which both sides of the Janus Ru‐W 2 C Schottky junction simultaneously dissociate water, serving as “dual channels” to supply H* to the interfacial active sites. Enabled by the “dual‐channel H supply” mechanism, the HER proceeds with a low energy barrier and a short reaction pathway, allowing the corresponding alkaline anion‐exchange membrane water electrolyzer to operate stably at 1.79 V and 1.0 A cm −2 for over 400 h. This work demonstrates that the precise Janus design serves as an effective strategy to achieve the “dual‐channel H* supply” in alkaline HER, thereby providing novel perspectives for the design of catalysts in hydrogen‐related reactions.