Computational Design of Metal–Organic Frameworks Based on Stable Zirconium Building Units for Storage and Delivery of Methane

A metal–organic framework (MOF) with high volumetric deliverable capacity for methane was synthesized after being identified by computational screening of 204 hypothetical MOF structures featuring (Zr<sub>6</sub>O<sub>4</sub>)­(OH)<sub>4</sub>(CO<sub>2</sub>)<sub>n</sub> inorganic building blocks. The predicted MOF (<b>NU-800</b>) has an <b>fcu</b> topology in which zirconium nodes are connected via ditopic 1,4-benzenedipropynoic acid linkers. Based on our computer simulations, alkyne groups adjacent to the inorganic zirconium nodes provide more efficient methane packing around the nodes at high pressures. The high predicted gas uptake properties of this new MOF were confirmed by high-pressure isotherm measurements over a large temperature and pressure range. The measured methane deliverable capacity of <b>NU-800</b> between 65 and 5.8 bar is 167 cc­(STP)/cc (0.215 g/g), the highest among zirconium-based MOFs. High-pressure uptake values of H<sub>2</sub> and CO<sub>2</sub> are also among the highest reported. These high gas uptake characteristics, along with the expected highly stable structure of <b>NU-800</b>, make it a promising material for gas storage applications.