Synergistic Ultrasound-Photo Enhancement of Ferroelectric Catalysis via Molecular Multiferroics

Molecular multiferroics have garnered significant attention for their exceptional responsiveness to external stimuli, demonstrating remarkable potential in multi-state information storage and sensing technologies. However, their catalytic capabilities remain underexplored. Here, the first demonstration of molecular multiferroic, N-ethyl-N-(fluoromethyl)-N-methylethanaminium tetrabromoferrate(III) (DEFM-FeBr₄) is presented, achieving efficient catalytic oxidation of alkanes through synergistic multifield activation. Under concurrent ultrasonic and light irradiation, DEFM-FeBr₄ exhibits outstanding catalytic performance in the oxidation of ethylmethylbenzene, achieving a turnover number (TON) of 1942-a 29-fold enhancement in activity compared to the inorganic ferroelectric barium titanate (BaTiO₃). The material demonstrates excellent recyclability and broad substrate compatibility across diverse alkanes, underscoring its practical advantages in heterogeneous catalysis. Mechanistic investigations via scanning kelvin probe microscopy (SKPM) and electron paramagnetic resonance (EPR) reveal that the intrinsic ferroelectric polarization facilitates the efficient separation of photogenerated charge carriers through built-in electric field modulation, thereby significantly enhancing catalytic activity. This work not only establishes molecular multiferroics as a new paradigm in catalytic materials science but also provides fundamental insights for designing advanced multiferroic catalysts with optimized multifield-responsive properties. This multiferroic catalysis strategy opens new avenues for developing smart catalytic systems with dynamically tunable reactivity.