Ultrafast Thermal Shock Synthesis of CuNiSnLa Medium‐Entropy Metallic Glass for Sustainable Nitrogen Fixation via Plasma‐Coupled Electrocatalysis

ABSTRACT The tandem integration of plasma‐based air oxidation and the electrochemical conversion of nitrate to ammonia (NO 3 RR) presents a transformative pathway for distributed green fertilizer production and carbon‐free fuel synthesis from air. However, NO 3 RR suffers from sluggish kinetics, as conventional synthesis methods with slow thermal rates fail to engineer closely adjacent active sites with the broad adsorption energy spectra required to satisfy the distinct adsorption energy needs of cascading elementary steps. Herein, we report a strategy utilizing ultrafast thermal pulses via two‐step Joule heating to synthesize a long‐range disordered CuNiSnLa medium‐entropy metallic glass (MEMG) featuring dense, synergistic catalytic sites with broad adsorption energy spectra. This ultrafast thermal shock effectively freezes the long‐range atomic diffusion driven by the repulsive interactions between immiscible elements, yielding a diverse landscape of active sites that can simultaneously optimize the sequential elementary reaction steps, demonstrating high ammonia yield rate and Faradaic efficiency at low overpotential. Beyond half‐cell tests, a practical rechargeable Zn‐nitrate device affords a 1.465 V open‐circuit potential, alongside a peak power density reaching 6.1 mW cm −2 . Furthermore, a fluid stack incorporating seven 64 cm 2 electrodes demonstrates excellent scalability, underscoring the potential of this system for large‐scale, renewable‐driven nitrogen fixation from air.