Application of metal–organic frameworks with coordinatively unsaturated metal sites in storage and separation of methane and carbon dioxide

The metal–organic frameworks M2(dhtp)(H2O)2·8H2O (CPO-27-M, M = Ni, Mg) can be activated to give the empty framework compounds M2(dhtp) with a honeycomb analogous structure containing large micropores of 11–12 Å diameter and a high concentration of open metal sites. These sites play a major role in the adsorption of methane and carbon dioxide, which was studied at pressures up to 100 bar and 50 bar, respectively, and various temperatures in the range of 179 to 473 K. Both gases are taken up by the material in significant amounts. The maximum excess adsorption of CO2 observed at 298 K was 51 wt.% for Ni2(dhtp) and 63 wt.% for Mg2(dhtp). A surprisingly large amount of CO2, in the range 25–30 wt.%, was still…

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  Norges Forskningsråd