Interaction of Acid Gases SO2 and NO2 with Coordinatively Unsaturated Metal Organic Frameworks: M-MOF-74 (M = Zn, Mg, Ni, Co)

K. Tan, S. Zuluaga, H. Wang, P. Canepa, K. Soliman, J. Cure, J. Li, T. Thonhauser, Y. J. Chabal.; Chem. Mater. 29 (10), 4227–4235 (2017).

Abstract

In situ infrared spectroscopy and ab initio density functional theory (DFT) calculations are combined to study the interaction of the corrosive gases SO2 and NO2 with metal organic frameworks M-MOF-74 (M = Zn, Mg, Ni, Co). We find that NO2 dissociatively adsorbs into MOF-74 compounds, forming NO and NO3–. The mechanism is unraveled by considering the Zn-MOF-74 system, for which DFT calculations show that a strong NO2–Zn bonding interaction induces a significant weakening of the N–O bond, facilitating the decomposition of the NO2 molecules. In contrast, SO2 is only molecularly adsorbed into MOF-74 with high binding energy (>90 kJ/mol for Mg-MOF-74 and >70 for Zn-MOF-74). This work gives insight into poisoning issues by minor components of flue gases in metal organic frameworks materials.