A pomegranate-inspired B@(NH4)2SiF6@LiClO4 architecture for spatiotemporally coordinated boron combustion

Pomegranate-like B@(NH 4 ) 2 SiF 6 @LiClO 4 enables ordered boron combustion. • Sequential fluorination–oxidation suppresses oxide re-passivation. • The optimized composite shows faster ignition and stronger flames. Boron suffers from severely limited combustion efficiency due to the kinetic barrier imposed by its native oxide layer. In this work, a pomegranate-inspired B@(NH 4 ) 2 SiF 6 @LiClO 4 composite was fabricated via a two-step solvent evaporation-induced self-assembly strategy, enabling highly dispersed reactive domains and intimate interfacial contact. The distinctive pomegranate-inspired architecture establishes particle-level spatial organization of the reactive components, while their distinct thermal activation windows provide the temporal basis for a proposed spatiotemporally coordinated reaction pathway. TG-DSC and TG-FTIR analyses reveal that fluorine-containing species derived from (NH 4 ) 2 SiF 6 evolve prior to LiClO 4 melting and major oxidizer release, supporting a proposed sequential fluorination-oxidation pathway involving early fluorine-mediated interfacial modification followed by oxidizer-driven boron oxidation. At an optimal (NH 4 ) 2 SiF 6 content of 10 wt%, the ignition delay and combustion duration are reduced by 15.47% and 68.22%, respectively, compared with B@LiClO 4 , demonstrating substantially improved ignition and combustion kinetics. Combined structural, thermal, and combustion analyses support the proposed spatiotemporally coordinated fluorination-oxidation pathway arising from the coupling of particle-level organization and temporally separated thermal events. This work provides a particle-level interfacial engineering strategy for coordinating fluorination and oxidation in high-performance boron-based energetic systems. A pomegranate-inspired B@(NH₄)₂SiF₆@LiClO₄ enables spatiotemporally ordered boron combustion by coupling fluorination and oxidation reactions within confined nanoscale domains. Sequential interfacial activation and molten-salt-mediated oxygen transport promote continuous reaction propagation and suppress oxide re-passivation, resulting in faster ignition, intensified flame propagation, and more efficient energy release compared with conventional physically mixed systems. Download: Download high-res image (176KB) Download: Download full-size image