Fundamental Aspects of H₂S Adsorption on CPO-27-Ni

Adsorption of H₂S on the Ni2(dhtp)(H₂O)2·8H2O metal–organic framework (known as CPO-27-Ni or MOF-74-Ni) is characterized by in situ powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR), Raman, and UV–visible spectroscopy) and by first-principles periodic boundary conditions calculations. PXRD results show very high stability of CPO-27-Ni framework in the presence of H₂S. Nevertheless, as evidenced by change in color of the sample from pale yellow to dark green, the adsorption of H₂S strongly affects the coordination of Ni sites. FTIR results show the reversible molecular adsorption of H₂S. Experimental and computed energies of interaction reveal good agreement. Quantitative data considering energetic aspects (calorimetric measurements) are also included. This work highlights the fundamentals of H₂S adsorption onto the CPO-27-Ni framework.