Super Metallated Frameworks as Hydrogen Sponges

Recipient University of California, Berkeley (PI: Omar Yaghi)

Abstract Metal-organic frameworks (MOFs) are crystalline porous materials composed of metal cluster nodes linked by organic struts where each component can be altered or functionalized systematically. This tunability coupled with the highly porous nature of MOFs make them ideal for gas storage applications. The state-of-the-art MOF based absorbent (MOF-74 analogue) utilizes coordinatively unsaturated metal sites (open metal sites) which exhibit strong interaction with H2 (13 KJ/mol) producing the record figure of merit (12 g/L and 0.9 wt% at 25 ºC 100 bar). However, these values remain below the DOE 2025 target. To address this issue, we propose to utilize molecular chemistry to integrate a highly reactive network (open metal sites linked with metal binding motifs) into a highly robust and porous framework (MOF) with open metal sites and achieve unprecedented high capacity for H2 storage.