(297g) Partially Unzipped Boron Nitride Embeds Magnesium Nanoparticles for Fast and High-Density Hydrogen Storage

Hydrogen fuel is promising for automotive use, but safe, high-density solid-state storage remains a challenge. Magnesium (Mg) offers potential due to its ability to form MgH₂ under moderate conditions. However, its high formation enthalpy (~75 kJ/mol) demands elevated release temperatures. Embedding Mg in dense matrices reduces particle size, shortens diffusion paths, and enhances reactivity, improving hydrogen binding. Yet, nanoparticle synthesis faces issues like size instability and oxidation due to poor matrix compatibility. In this study, we use boron nitride (BN) as a stabilizing matrix, leveraging its partial “unzipping” under oxidative dehydrogenation of propane (ODHP) to create anchoring sites for Mg. FT-IR confirmed B–O and OH groups post-treatment, indicating successful functionalization. The resulting Mg–BN nanocomposite stored 6.92 wt.% H₂ at 200 °C and 35 bar, with a low desorption activation energy of 46.2 kJ/mol. Five hydrogen charge–discharge cycles demonstrated rapid hydrogen release and stable performance, indicating that BN effectively embedded Mg nanoparticles, accommodating expansion and contraction without fracture or macroscale sintering. This “partial unzipping and chemical sewing” method provides a scalable approach for Mg-based hydrogen storage.