Molecular chemisorption on open metal sites in Cu3(benzenetricarboxylate)2: A spatially periodic density functional theory study

Chemical interactions of H2O, CO, NO, pyridine, C2H2, H2S, and NH3 with open metal sites in the metal-organic framework (MOF) Cu3(benzenetricarboxylate)2 are examined using plane wave periodic density functional theory (DFT). In the case of single molecule adsorption on a Cu dimer, NH3 and pyridine have the strongest binding, while NO binds weakly. Binding of pairs of molecules on a Cu dimer shows significant interaction energies, that is, the binding energy of the pair of molecules is not a simple summation of the binding energies of each molecule. The effect of molecular adsorption on the magnetic moments of Cu atoms in the MOF is also examined. Using the binding energies from DFT calculations, the effects of the pressure and temperature on the chemisorbed species are investigated. Finally the effect of water adsorption on the elastic behavior of Cu3(BTC)2 is described.