An Atomic‐Level Bimetallic MOF Platform Overcoming the Stability‐Performance Tradeoff for Laser Propulsion

ABSTRACT This work establishes a materials design paradigm that achieves simultaneous enhanced stability and performance for photon‐based propulsion. We introduce an atomic‐level bimetallic platform to overcome the inherent trade‐off between high thrust efficiency and environmental stability, particularly against hydrolysis. This is achieved through bimetallic FeCu‐MOFs synthesized via a one‐step laser synthesis, where Fe 3+ and Cu 2+ co‐crystallize with tricarboxylate ligands to form an isomorphous HKUST‐1 derivative. This approach exploits hard‐soft acid‐base principles to achieve several fundamental advances: enhanced bond strength, hydrolytic and thermal stability through the formation of robust Fe‐O bonds, increasing water resistance by 20 times while preserving crystalline integrity; synergistic, delocalized energy dissipation via d‐orbital charge transfer (Fe 3+ →Cu 2+ ), boosting uniform photothermal conversion to 91%; and inherent stoichiometric tunability, where the Fe:Cu ratio serves as a precise performance lever, providing a design strategy to optimize stability and performance. The optimized FeCu‐MOF‐M variant achieves record propulsion metrics—impulse coupling coefficient (191.80 µN/W), specific impulse (631.19 s), thrust density (61.86 µN/µg), and ablation efficiency (59.32%) —surpassing monometallic HKUST‐1 by 15.7% and physical mixtures by 125%. By unifying hydrolysis resistance, efficient photothermal conversion, and atomic‐level tunability, this stoichiometry‐driven photothermal synergy bimetallic frameworks provides a solid foundation for next‐generation energetic materials in demanding environments.