Hydrogen storage and mobility determined by NMR to various organically functionalized porous silica synthetized by using the post-grafting method

The results of this study will help in guiding the future design of low-cost and highly performing functionalized mesoporous silica using cationic surfactants as directing agents. Indeed, by properly tuning surface interactions and the textural characteristics, the overall efficiency of H2 capture processes could be improved. Among different synthetized sam-ples, the experimental results show the better interaction with (3-Aminopropyl)triethox-ysilane precursor. Furthermore, an NMR investigation aiming at clarifying the internal arrangement and diffusion properties of hydrogen molecules inside functionalized porous silica materials has been performed. The NMR spectral analysis and the T1 relaxation times indicated two different populations for H2 sorbate due to the molecules adsorbed in mesopores and in micropores. For the first time, the H2 self-diffusion coefficient in func-tionalized silica has been experimentally measured by pulsed field gradient NMR. The spin -echo decay revealed two different diffusion mechanisms coexist in the functionalized mesoporous silica, except for the material functionalized with iodopropyl groups, which shows a single diffusion coefficient. & COPY; 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The results of this study provide guidance for the future design of low-cost and high-performance functionalized mesoporous silica using cationic surfactants as directing agents. The tuning of surface interactions and textural characteristics can improve the efficiency of H2 capture processes. Experimental results show that the (3-Aminopropyl)triethoxysilane precursor has better interaction. NMR investigation reveals the internal arrangement and diffusion properties of hydrogen molecules in functionalized porous silica materials, with two different diffusion mechanisms observed in functionalized mesoporous silica.