Entropy-Assisted Thermodynamic Frustration Enables Durable Amorphous Multimetallic TMD Catalysts for High-Current Acidic Hydrogen Evolution

Abstract Stabilizing highly active yet metastable catalytic phases remains a central challenge in hydrogen evolution reaction (HER) electrocatalysis. Here, we report a phase-equalization strategy that enables the stabilization of a W6+–Se–based amorphous state in multimetallic transition metal dichalcogenides (TMDs) under acidic HER conditions. By deliberately tuning the formation energy difference between the 1T and 2H phases through W-rich and chalcogen-rich precursor design, we establish a distorted structural template that undergoes controlled amorphization during postannealing. Unlike Mo-rich systems, which exhibit a strong thermodynamic driving force toward 2H crystallization, W-rich compositions suppress long-range ordering and favor the formation of a structurally dominant amorphous phase. X-ray photoelectron spectroscopy and Se K-edge XANES/EXAFS analyses reveal the emergence of distinct W6+–Se coordination motifs that are absent in conventional crystalline TMDs. This unconventional local structure correlates with enhanced hydrogen adsorption characteristics and improved charge-transfer kinetics. Furthermore, entropy-mediated incorporation of 3d transition metals (e.g., Ni) reduces the formation energy disparity between crystalline phases, enabling complete amorphization through short-range atomic migration during annealing. The resulting amorphous alloy TMD catalysts exhibit an overpotential below 125 mV at 10 mA cm–2 and sustain continuous operation at 200 mA cm–2 for over 55 h in acidic electrolyte without noticeable degradation. Beyond introducing multimetallic amorphous TMD catalysts, this work establishes a general principle: when competing crystalline phases possess comparable formation energies, postannealing drives amorphization rather than crystallization, providing a pathway to stabilize metastable active states for durable HER electrocatalysis.