Selective adsorption of sulphur dioxide and hydrogen sulphide by metal-organic frameworks

• Published in: Physical chemistry chemical physics : PCCP 2023-01, Vol.25 (2), p.954-965
• Main Authors: Grubišić, S, Dahmani, R, Djordjević, I, Sentić, M, Hochlaf, M
• Format: Article
• Language: English
• Subjects: Acid resistance; Adsorption; Bonding strength; Carbon dioxide; Chemical Sciences; Density functional theory; First principles; Hydrogen bonds; Hydrogen sulfide; Low pressure; Metal-organic frameworks; Moisture effects; Moisture resistance; Selective adsorption; Selectivity; Sulfur dioxide; Sulfur dioxide recovery; Surface chemistry; Thermal stability; Water chemistry
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d2cp04295a

The removal of highly toxic gasses such as SO and H S is important in various industrial and environmental applications. Metal organic frameworks (MOFs) are promising candidates for the capture of toxic gases owing to their favorable properties such as high selectivity, moisture stability, thermostability, acid gas resistance, high sorption capacity, and low-cost regenerability. In this study, we perform first principles density functional theory (DFT) and grand-canonical Monte Carlo (GCMC) simulations to investigate the capture of highly toxic gases, SO and H S, by the recently designed ZTF and MAF-66 MOFs. Our results indicate that ZTF and MAF-66 show good adsorption performances for SO and H S capture. The nature of the interactions between H S or SO and the pore surface cavities was examined at the microscopic level. SO is adsorbed on the pore surface through two types of hydrogen bonds, either between O of SO with the closest H of the triazole 5-membred ring or between O of SO with the hydrogen of the amino group. For H S inside the pores, the principal interactions between H S and surface pores are due to a relatively strong hydrogen bonds established between the nitrogens of the organic part of MOFs and H S. Also, we found that these interactions depend on the orientation of SO /H S inside the pores. Moreover, we have studied the influence of the presence of water and CO on H S and SO capture by the ZTF MOF. The present GCMC simulations reveal that the addition of H O molecules at low pressure leads to an enhancement of the H S adsorption, in agreement with experimental findings. However, the presence of water molecules decreases the adsorption of SO irrespective of the pressure used. Besides, SO adsorption is increased in the presence of a small number of CO molecules, whereas the presence of carbon dioxide in ZTF pores has an unfavorable effect on the capture of H S.