Development of exfoliated layered stannosilicate for hydrogen adsorption

摘要

The use of hydrogen as an energy vector leads to the development of materials with high hydrogen adsorption capacity. In this work, a new layered stannosilicate, UZAR-S3, is synthesized and delaminated, producing UZAR-S4. UZAR-S3, with the empirical formula Na_4SnSi_5O_(14)•3.5H_2O and lamellar morphology, is a layered stannosilicate built from SnO_6 and SiO_4 polyhedra. The delamination process used here comprises three stages: protonation with acetic acid, swelling with nonylamine and the delamination itself with an HCl/H_2O/ethanol solution. UZAR-S4 is composed of sheets a few nanometers thick with a high aspect ratio and a surface area of 236 m~2/g, twenty times higher than that of UZAR-S3. At-196℃ for UZAR-S4, H_2 adsorption reached remarkable values of 3.7 and 4.2 wt% for 10 and 40 bar, respectively, the latter value giving a high volumetric H_2 storage capacity of 26.2 g of H_2/L.