Neutron Diffraction Studies of Metal-Organic Frameworks for Ammonia Adsorption

Porous metal-organic frameworks (MOFs) are gaining increasing attention due to their recently commercialised application in gas adsorption. There is a strong interest in ammonia adsorption owing to the high volumetric and gravimetric hydrogen energy density of ammonia. We seek to develop MOF materials with exceptional ammonia capacity and request 4 days on WISH to study the preferred binding sites and orientation of adsorbed ND3 molecules in the MOFs. This proposed study will investigate the precise locations of ND3 and CO2 molecules within two robust MOFs, namely Al-BTA-1 and Al-BTA-2. These MOFs exhibit exceptionally high capacity for ammonia at extremely low concentration with repeatable cycles, representing the best-performing materials to date. The high resolution, low background and large d-spacing capabilities of WISH will enable structural insight to study the precise locations and preferred orientation of ND3 molecules. The proposed study aims to reveal the change in host-guest interaction with respect to different surface coverage.