Surprising role of the BDC organic ligand in the adsorption of CO2 by MOF-5

The GCMC simulation of CO2 adsorption in MOF-5 is revisited, finding a surprising role of the BDC organic ligand in this process. A novel structure partition methodology is introduced to decompose the relative contributions of the metal oxoclusters and the organic ligands. The origin of the primary step in the CO2 adsorption isotherm in MOF-5 is explained by a synergistic effect arising from specific short-range interactions between the sorbate and the MOF components with equal contributions from both the metal oxocluster and the organic ligand, together with an additional contribution due to the nano-confinement of the adsorbate. (C) 2012 Elsevier Inc. All rights reserved.