Hydrogen Storage in a Potassium-Ion-Bound Metal-Organic Framework Incorporating Crown Ether Struts as Specific Cation Binding Sites

Abstract

To develop a metal-organic framework (MOF) for hydrogen storage, SNU-200 incorporating a 18-crown-6 ether moiety as a specific binding site for selected cations has been synthesized. SNU-200 binds K+, NH4+, and methyl viologen( MV2+) through single-crystal to single-crystal transformations. It exhibits characteristic gas-sorption properties depending on the bound cation. SNU-200 activated with supercritical CO2 shows a higher isosteric heat (Q(st)) of H-2 adsorption (7.70 kJ mol(-1)) than other zinc-based MOFs. Among the cation inclusions, K+ is the best for enhancing the isosteric heat of the H-2 adsorption (9.92 kJ mol(-1)) as a result of the accessible open metal sites on the K+ ion.