Effect of high pressure CO2 sorption on the stability of metalorganic framework MOF-177 at different temperatures

Abstract

The large volumes of natural gas production mean that the processes currently used in the oil industry no longer meet such demand. Therefore, there is an expectation that adsorption processes will reach up to 200 bar in order to process the large volume of natural gas produced. However, it is not known if the materials used in this process would remain stable after being subjected to high pressures. In this way, sorption studies of host molecules such as CO2 at high pressures are important to understand the structural, thermal and chemical changes of this material. Therefore, the objective of this work is to perform stability experiments with MOF-177 using CO2 in an equilibrium cell at a fixed pressure of 200 bar at different temperatures of 20 °C, 40 °C and 60 °C for 12 h. The X-ray diffraction measurements showed that the metal-organic structure underwent irreversible amorphization with increasing temperature. The samples treated at 20 °C and 40 °C did not show significant surface area changes. However, at 60 °C there was an expressive reduction. All samples showed thermal stability up to 400 °C. By means of the FT-IR and SEM analysis, it was possible to observe that there was no chemical and morphological change in the MOF-177 and in the samples submitted to high pressure at different temperatures.