Tailored Entropy State of Atomic‐Thick High‐Entropy Analog Layer‐Stacked Tetra‐Metallic Hydroxide Surface Enables Efficient Durable Hydrogen Production

The development of high‐efficiency electrocatalysts for green hydrogen production via electrochemical water electrolysis is crucial for addressing the future energy crisis. Herein, a particular engineering approach is employed to tailor the entropy state by integrating the medium/high‐entropy hybrid concept, utilizing an atomic‐thick NiFeCoMnPt high‐entropy analog layer‐coated 2D tetra‐metallic NiFeCoMn double‐layered hydroxide nanosheet‐like structure (NFCM−NFCMP LDH). The NFCM−NFCMP LDH material demonstrates outstanding hydrogen and oxygen evolution performances in 1.0 M KOH medium with a required overpotential of only 72 and 220 mV, respectively, to reach a current density of 10 mA·cm −2 , thus resulting in a small cell voltage of 1.53 V for overall water splitting, and an advanced mass activity of 0.63 at 1.75 V, approximately 5.7‐fold higher than that of commercial Pt/C (−) //RuO 2(+) . The NFCM−NFCMP LDH (+,−) couple‐derived anion exchange membrane electrolyzer requires a cell voltage of 1.75/2.12 V to operate at 0.5/1.0 A·cm −2 at 60°C and maintain stability for 1000 h. Theoretical studies reveal that unique interactions between atomic sites within the atomic high‐entropy‐like surface layer and between the NFCMP and NFCM LDH structures drive surface reconstruction, creating optimized electronic configurations that promote robust, high‐performance catalysis.