High Hydrogen Storage in Trigonal Prismatic Monomer-Based Highly Porous Aromatic Frameworks.

Kim, Dae Won; Chen, Yu; Kim, Hyunlim; Kim, Namju; Lee, Young Hoon; Oh, Hyunchul; Chung, Yongchul G; Hong, Chang Seop · Adv Mater · 2024

basic_science · Level V

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Abstract

Hydrogen storage is crucial in the shift toward a carbon-neutral society, where hydrogen serves as a pivotal renewable energy source. Utilizing porous materials can provide an efficient hydrogen storage solution, reducing tank pressures to manageable levels and circumventing the energy-intensive and costly current technological infrastructure. Herein, two highly porous aromatic frameworks (PAFs), C-PAF and Si-PAF, prepared through a Yamamoto C─C coupling reaction between trigonal prismatic monomers, are reported. These PAFs exhibit large pore volumes and Brunauer-Emmett-Teller areas, 3.93 cm<sup>3</sup> g<sup>-1</sup> and 4857 m<sup>2</sup> g<sup>-1</sup> for C-PAF, and 3.80 cm<sup>3</sup> g<sup>-1</sup> and 6099 m<sup>2</sup> g<sup>-1</sup> for Si-PAF, respectively. Si-PAF exhibits a record-high gravimetric hydrogen delivery capacity of 17.01 wt% and a superior volumetric capacity of 46.5 g L<sup>-1</sup> under pressure-temperature swing adsorption conditions (77 K, 100 bar → 160 K, 5 bar), outperforming benchmark hydrogen storage materials. By virtue of the robust C─C covalent bond, both PAFs show impressive structural stabilities in harsh environments and unprecedented long-term durability. Computational modeling methods are employed to simulate and investigate the structural and adsorption properties of the PAFs. These results demonstrate that C-PAF and Si-PAF are promising materials for efficient hydrogen storage.