Magnetic-Field-Enabled Ultrafast Quench Synthesis of Single-Atom Catalysts for Efficient Anion Exchange Membrane Water Electrolysis

Single-atom catalysts (SACs) play a critical role in diverse catalytic applications, but their efficient synthesis remains a significant challenge. Herein, we develop an ultrafast magnetic-field-enabled quench (MFEQ) strategy to synthesize a series of M₁/G-FeO_x (M═Ni, Fe, Co, Ir, Ru, and Pt) SACs within a few seconds. Using Ni₁/G-FeO_x as a proof of concept, this method leverages the rapid quenching of thermally incandescent Fe foam into an Ni-containing ethanol solution, triggering simultaneous graphene formation and Ni anchoring. The Ni₁/G-FeO_x catalyst shows exceptional alkaline oxygen evolution reaction (OER) performance, operating at 200 mV for 10 mA cm⁻² and sustaining 105 mA cm⁻² for 330 h without degradation. Notably, the Ni₁/G-FeO_x-catalyzed anion exchange membrane water electrolysis (AEMWE) device exhibits a low voltage of 1.86 V at 1.0 A cm⁻² and 600 h long-term stability. Density functional theory (DFT) calculations and experiments reveal that the strong electronic interactions between Ni₁/G and FeO_x contribute to the optimized electronic structure and reduced energy barrier. Techno-economic analysis (TEA) highlights the superior energy efficiency of the MFEQ method, which requires only US$19.2 in energy expenditure to synthesize 1 kg of SACs. This work provides new insights into the ultrafast fabrication of SACs.