Zhang Xin, Lin Rui-Biao, Wang Jing, Wang Bin, Liang Bin, Yildirim Taner, Zhang Jian, Zhou Wei, Chen Banglin
Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX, 78249-0698, USA.
College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, 310014, China.
Adv Mater. 2020 Apr;32(17):e1907995. doi: 10.1002/adma.201907995. Epub 2020 Mar 18.
Metal-organic frameworks (MOFs) are promising materials for onboard hydrogen storage thanks to the tunable pore size, pore volume, and pore geometry. In consideration of pore structures, the correlation between the pore volume and hydrogen storage capacity is examined and two empirical equations are rationalized to predict the hydrogen storage capacity of MOFs with different pore geometries. The total hydrogen adsorption under 100 bar and 77 K is predicted as n = 0.085× V - 0.013× V for cage-type MOFs and n = 0.076× V - 0.011× V for channel-type MOFs, where V is the pore volume of corresponding MOFs. The predictions by these empirical equations are validated by several MOFs with an average deviation of 5.4%. Compared with a previous equation for activated carbon materials, the empirical equations demonstrate superior accuracy especially for MOFs with high surface area (i.e., S over ≈3000 m g ). Guided by these empirical equations, a highly porous Zr-MOF NPF-200 (NPF: Nebraska Porous Framework) is examined to possess outstanding hydrogen total adsorption capacity (65.7 mmol g ) at 77 K and record high volumetric working capacity of 37.2 g L between 100 and 5 bar at 77 K.
金属有机框架材料（MOFs）因其可调的孔径、孔体积和孔几何形状，是用于车载储氢的有前景的材料。考虑到孔结构，研究了孔体积与储氢容量之间的相关性，并推导了两个经验方程来预测不同孔几何形状的MOFs的储氢容量。对于笼型MOFs，在100 bar和77 K下的总氢吸附量预测为n = 0.085×V - 0.013×V，对于通道型MOFs，为n = 0.076×V - 0.011×V，其中V是相应MOFs的孔体积。这些经验方程的预测结果通过几种MOFs得到验证，平均偏差为5.4%。与之前针对活性炭材料的方程相比，这些经验方程显示出更高的准确性，特别是对于高表面积（即S超过≈3000 m²/g）的MOFs。在这些经验方程的指导下，研究发现一种高度多孔的Zr-MOF NPF-200（NPF：内布拉斯加多孔框架）在77 K时具有出色的总氢吸附容量（65.7 mmol/g），并且在77 K下100至5 bar之间的体积工作容量达到创纪录的37.2 g/L。
