A Microporous Copper Metal-Organic Framework with High H2 and CO2 Adsorption Capacity at Ambient Pressure

摘要

Metal-organic frameworks (MOFs) as highly porous materials have gained increasing interest because of their distinct adsorption properties. They exhibit a high potential for applications in gas separation and storage, as sensors as well as in heterogeneous catalysis. In the last few years, the H2 storage capacity of MOFs has been considerably increased. Mesoporous MOFs show high adsorption capacities for CH4, CO2, and H2 at high pressures. To increase the uptake of H2 and CO2 by physisorption at ambient pressure, adsorbents with small micropores as well as high specific surface areas and micropore volumes are required. Such microporous materials seem to be more appropriate for gas-mixture separation by physisorption than mesoporous materials. For gas separation in MOFs the interactions between the fluid adsorptive and "open metal sites" (coordinatively unsaturated binding sites) or the ligands are regarded as important. Industrial processes, such as natural-gas purification or biogas upgrading, can be improved with those materials during a vapor-pressure swing adsorption cycle (VPSA cycle) or a temperature swing adsorption cycle (TSA cycle).