Exploring the Chemical Space of Metal-Organic Frameworks with rht Topology for High Capacity Hydrogen Storage

Published

May 9, 2024

Author(s)

Kunhuan Liu, Zhijie Chen, Timur Islamoglu, Seung-Joon Lee, Haoyuan Chen, Taner N. Yildirim, Omar Farha, Randall Snurr

Abstract

Hydrogen is considered a crucial clean energy vector to mitigate climate change, but due to the low volumetric energy density of gaseous hydrogen, it is difficult to store hydrogen for many practical applications. Cryogenic sorption-based methods, particularly using metal−organic frameworks (MOFs), have been considered as viable solutions to enhance the deliverable capacity of stored hydrogen, and among the many available MOFs, those with rht topology have demonstrated exceptional capacity. MOFs with rht topology are formed by the assembly of supermolecular building blocks (SBBs), but the diversity of SBBs in the literature on rht-MOFs is limited, resulting in an underexplored structural design space. In this study, we designed 380 MOFs made of 20 novel SBBs to investigate the effect of cavity size on hydrogen storage capacity and the underlying structure−property relationships. We performed grand canonical Monte Carlo simulations on 472 rht-MOFs, encompassing both existing and novel structures, to predict hydrogen loadings under cryogenic conditions (77 K/100 bar →160 K/5 bar) and to study the influence of SBB size and composition on the hydrogen uptake. Our simulations revealed the potential to achieve high volumetric capacities using a variety of SBBs as well as variations in excess uptake per surface area among different SBBs. Regression models were utilized to examine the correlations between the hydrogen capacities and textual properties such as crystal density, pore diameters, pore volume per unit mass, and surface area. We built a quantitative model to further understand the relation between pore volume and deliverable capacities. Notably, PCN-61 demonstrated the highest simulated volumetric deliverable capacity among the MOFs studied and corresponded to an ideal pore volume suggested by our model. The computational investigation was further validated by high-pressure gas adsorption measurements for PCN-61.

Citation

Journal of Physical Chemistry C

Volume

128

Issue

18

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acs.jpcc.4c00638

Local Download

Citation

Liu, K. , Chen, Z. , Islamoglu, T. , Lee, S. , Chen, H. , Yildirim, T. , Farha, O. and Snurr, R. (2024), Exploring the Chemical Space of Metal-Organic Frameworks with rht Topology for High Capacity Hydrogen Storage, Journal of Physical Chemistry C, [online], https://doi.org/10.1021/acs.jpcc.4c00638, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959158 (Accessed December 13, 2024)