Lithium-Induced Covalent Organic Frameworks with Enhanced Sorption Heat for Efficient Hydrogen Storage
Zhuozhuo Tang, Jia Chen, Yulong Xu, Zonglong Li, Li Sheng, Yang Hu, Xiaolin Wang, Jianlong Wang, Yaping Tang, Xiangming He, Hong Xu
Abstract
Covalent organic frameworks (COFs) possess high surface areas and tunable pore structures and are promising candidates for H 2 physisorption materials. However, their interaction with H 2 molecules is too weak to take advantage of the high porosity of the COFs. Here, we report the first example of metal-doped enhanced H 2 -physisorption COF. By leveraging the superior stability of TPB-DMTP-COF, we can well preserve the porosity of the COF after lithium (Li) doping, yielding a surface area of 1350 m 2 /g. Due to the Li-doping-enhanced H 2 isosteric heat, the material’s total H 2 uptake increased from 4.98 to 6.91 wt % at 77 K and 80 bar. The Li-doping-induced enhancement effect does not involve chemisorption, and the material shows excellent cycling performance: 10 cycles at 30 bar with a capacity retention of 99%. Our results reveal that tuning H 2 adsorption heat by postmodification is a promising strategy to exploit the potential of porous materials for efficient H 2 storage.