Chemical Stability of MIL-101(Cr) upon Adsorption of SO<sub>2</sub> and NO<sub>2</sub> under Dry and Humid Conditions
Eli A. Carter, Julian T. Hungerford, Jayraj N. Joshi, Stephen J. A. DeWitt, Xiao Jiang, Bartosz Marszałek, Ryan P. Lively, Krista S. Walton
Abstract
High Resolution Image Download MS PowerPoint Slide A detailed understanding of the chemical stability of metal–organic frameworks (MOFs) in water and acidic and basic solutions currently exists; however, there has been comparatively little investigation into the chemical stability of MOFs in the presence of acid gas species that may be present in industrial settings. MIL-101(Cr), a MOF that is stable in liquid water as well as acidic and basic solutions, was tested for its stability upon exposure to the acid gases sulfur dioxide (SO 2 ) and nitrogen dioxide (NO 2 ). Successive breakthrough experiments of both SO 2 and NO 2 show that both gases lower the adsorption capacity of MIL-101(Cr), which is also observed by N 2 physisorption experiments. X-ray photoelectron spectroscopy (XPS) confirms the presence of sulfur and nitrogen species in MIL-101(Cr) after exposure to SO 2 and NO 2 species. In situ infrared spectroscopy experiments suggest that adsorption of SO 2 in MIL-101(Cr) is not completely reversible and that adsorption of NO 2 in MIL-101(Cr) causes some structural degradation similar to what has been previously observed in HKUST-1.