Exceptionally High Acetylene Uptake in a Microporous Metal−Organic Framework with Open Metal Sites

Six prototype microporous metal-organic frameworks (MOFs) HKUST-1, MOF-505, MOF-508, MIL-53, MOF-5, and ZIF-8 with variable structures and porosities were examined for their acetylene storage, highlighting HKUST-1 as the highest acetylene storage material ever reported with an uptake of 201 cm(3)/g at 295 K and 1 atm. To locate the acetylene binding sites within HKUST-1, neutron powder diffraction studies on acetylene loaded HKUST-1 were carried out and have conclusively established the significant contribution of open Cu(2+) sites for acetylene storage by their strong preferred interactions with acetylene molecules. The binding properties of acetylene gas at different sites were further investigated by first-principles calculations.