Investigation of the CO2 adsorption on Cu-BTC by combining vibrational spectroscopy and molecular dynamics

Metal-Organic Frameworks (MOFs) are a novel class of materials with promising performances in the field of gas adsorption due to their high specific area and stable nanoporous network. It has been demonstrated that by tailoring the nanocavities size and the nature of specific chemical interaction sites, it is possible to obtain high selectivity for low molecular weight compounds. The adsorption capability is highly affected by the presence of water, which can directly influence both the structure of the material and the amount of available interaction sites. In particular, Cu-BTC MOF is widely adopted for CO2 capture. In this work, we provide information at molecular level on the mechanism of CO2 adsorption in Cu-BTC, through "in situ" quantitative spectroscopic investigation at various temperature, and CO2 pressure. The experimental results have been integrated with molecular dynamics simulations, based on a force field already available in literature, to shed light on the role of interaction sites and of induced structural modifications.