Fine Tuning of MOF‐505 Analogues To Reduce Low‐Pressure Methane Uptake and Enhance Methane Working Capacity

Abstract

We present a crystal engineering strategy to fine tune the pore chemistry and CH₄ -storage performance of a family of isomorphic MOFs based upon PCN-14. These MOFs exhibit similar pore size, pore surface, and surface area (around 3000 m² g^-1 ) and were prepared with the goal to enhance CH₄ working capacity. [Cu₂ (L2)(H₂ O)₂ ]_n (NJU-Bai 41: NJU-Bai for Nanjing University Bai's group), [Cu₂ (L3)(H₂ O)₂ ]_n (NJU-Bai 42), and [Cu₂ (L4)(DMF)₂ ]_n (NJU-Bai 43) were prepared and we observed that the CH₄ volumetric working capacity and volumetric uptake values are influenced by subtle changes in structure and chemistry. In particular, the CH₄ working capacity of NJU-Bai 43 reaches 198 cm³ (STP: 273.15 K, 1 atm) cm^-3 at 298 K and 65 bar, which is amongst the highest reported for MOFs under these conditions and is much higher than the corresponding value for PCN-14 (157 cm³ (STP) cm^-3 ).