Compressive Strain in N‐Doped Palladium/Amorphous‐Cobalt (II) Interface Facilitates Alkaline Hydrogen Evolution

Abstract The development of palladium‐based catalysts for alkaline hydrogen evolution reaction (HER) is highly desired for renewable hydrogen energy systems, yet still challenging due to the strong palladium–hydrogen bond. Herein, the bottleneck is largely overcome by constructing a nitridation‐induced compressively strained‐interface N‐doped palladium/amorphous cobalt (II) interface (N‐Pd/A‐Co(II)), which dramatically boosts HER performance in alkaline condition. The optimized catalyst with the compressive strain of 2.7% exhibits the higher activity with an overpotential of only 58 mV to achieve the current density of 10 mA cm⁻², much better than those of pure Pd (327 mV), and the state‐of‐art Pt/C (78 mV). Notably, it also shows excellent stability with negligible decline during a 30 h stability test. Detailed analyses reveal that the strong absorption of H_ads on Pd can be efficiently reduced via the compressively strained N‐doped Pd. And the amorphous Co(II) component accelerates the water dissociation. Consequently, the cooperative effect between the compressed N‐doped Pd and amorphous Co(II) creates the impressive HER performance in alkaline condition, highlighting the importance of the functional interface to develop efficient electrocatalysts for HER and beyond.