Simultaneous Nanoconfinement and Catalysis in a Metal–Halloysite Hybrid Sponge for Accelerated and Clean Hydrogen Production from Ammonia Borane

The rapid development of efficient hydrogen storage systems has significantly advanced large-scale hydrogen energy applications in fuel cells. In this study, we report a novel hydrogen storage strategy involving the loading of ammonia borane (AB) and ruthenium nanoparticle catalysts into a halloysite nanotube (HNT) inorganic sponge (Ru/HP) for low-temperature thermal dehydrogenation of AB to release high-purity hydrogen. Attributing to the synergistic effects of the nanoconfinement of HNT-based porous sponge and the catalysis of ruthenium nanoparticles, the thermal dehydrogenation performance of AB@Ru/HP is significantly improved with boosted reaction kinetics and lowered dehydrogenation temperature (60 °C). Beyond that, AB@Ru/HP also avoids volume expansion and the emission of byproducts such as ammonia, diborane, and borazine during pyrolysis. The activation energy of AB@Ru/HP (50.13 kJ mol–1) is substantially lower than that of pure AB (160 kJ mol–1) and AB@HP (110.55 kJ mol–1). Important of all, the Ru/HP sponge demonstrates an encapsulation ratio for AB (23%), as well as excellent recyclability and reusability. This work presents a viable strategy for developing efficient and cost-effective hydrogen storage systems through the thermal dehydrogenation of AB confined within a catalyst-loaded inorganic HNT sponge.