(675d) Acid Gas Adsorption on Metal–Organic Framework Nanosheets As a Model of an “All-Surface” Material
AIChE Annual Meeting
Thursday, November 2, 2017 - 9:00am to 9:15am
Furthermore, we study adsorption of a set of acid gases to the exposed OMSs (open metal sites) existing at the surface of these materials in the presence of water, including competing co-adsorption motif and cooperative co-adsorption motif. Our computational results suggest that preadsorbed acid gases (CO2, SO2, NO2, and H2S) on Cu-BDC nanosheets would be replaced by water in the presence of water, leading to acid gas adsorbed on water coordinated OMSs instead of pure OMSs. For CO2 and H2S, the binding energies on water coordinated OMSs are lower than vacant OMSs, while for SO2 and NO2, the binding energies on water coordinated OMSs are higher. The strong double hydrogen bonds established by two oxygen atoms in SO2 and NO2 and two hydrogen atoms in water contribute to the enhanced binding energies. Even though water has a high probability to compete with acid gas for the same adsorption site, and even replace preadsorbed acid gases, in SO2 and NO2 cases, preadsorbing a small amount of water can increase the SO2 and NO2 binding strength and attack on Cu-BDC nanosheets.