An rht-type metal–organic framework constructed from an unsymmetrical ligand exhibiting high hydrogen uptake capability

Abstract

An unsymmetrical hexatopic carboxylate acid (H6-1) ligand containing one acrylamide unit and two triazole groups was designed and synthesized, and then used to construct a metal–organic framework (MOF Cu-ABTA) via a solvothermal reaction with Cu(NO₃)₂. A powder X-ray diffraction investigation indicated that the MOF Cu-ABTA possesses a (3,24)-connected rht-network, as does our previously reported MOF NTU-105 with three triazole groups. The gas sorption measurements revealed that Cu-ABTA shows high porosity and a very high H₂-uptake capability with a strong H₂ binding affinity as demonstrated by the enhanced isosteric heat of adsorption, which make it a highly promising candidate for clean energy storage.