Characterization of hydrogen/deuterium adsorption sites in nanoporous Cu-BTC by low-temperature thermal-desorption mass spectroscopy

Hydrogen and deuterium adsorption sites in the crystalline MOF copper(II) benzene-1,3,5-tricarboxylate, Cu-BTC were studied by low-temperature thermal desorption spectroscopy. For a maximum loading of 218 D(2) molecules per unit cell of Cu-BTC three desorption maxima were observed. The maxima could be separated by either interrupted desorption or partial loading. By comparing to neutron diffraction studies from the literature the maxima could be assigned to three different adsorption sites, i.e. coordinatively-unsaturated Cu(2+) sites, tetrahedral side pockets and the large pores. (C) 2011 Elsevier Inc. All rights reserved.