Hydrogen storage in porous aluminosilicate ceramics and light-metal hydrides: Physisorption-chemisorption interplay

Résumé fourni par la source

Efficient solid-state hydrogen storage remains a key challenge for hydrogen-based energy systems. In this work, porous aluminosilicate ceramics of the Al-SiO2 composition synthesized with combustible pore-forming additives and selected light-metal hydrides (LiH, TiH2, MgH2) were investigated as hydrogen storage media. The ceramics form a single-phase zeolite-type cubic structure with a = 4.056 Å and a hierarchical pore network (pore diameters 2–28 µm, porosity ≈ 44%) that supports gas transport. Hydrogenation experiments were performed in a high-temperature sealed reactor using gravimetric mass-gain measurements with explicit calibration, blank tests, and uncertainty analysis. Under optimal conditions (200 °C, 12 atm), the porous Al-SiO2 ceramics show a preliminary hydrogen storage capacity of up to 11 wt.% from mass-gain data, indicating strong potential but still requiring confirmation by standard P-C-T characterization. The storage mechanism combines physisorption on the porous framework with chemisorption and hydride-like phase formation (e.g., AlH3), and cyclic tests reveal noticeable structural degradation after about five sorption-desorption cycles. Comparative measurements show capacities of ≈0.7 wt.% for porous nickel, 1.5 wt.% for magnesium, 3.8 wt.% for titanium (near its 4.04 wt.% theoretical limit), and up to 12.4 wt.% for lithium at 700 °C and 12 atm, confirming the strong promise of porous aluminosilicates and light-metal hydrides for solid-state hydrogen storage.

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