Adsorption of CO₂ on amine-functionalized green metal-organic framework: an interaction between amine and CO₂ molecules

The efficient capture of CO₂ is a critical problem for porous adsorbents. The inadequacy of conventional adsorbents has low adsorption capacity towards CO₂ removal. Metal organic frame work has been considered as very effective for CO₂ adsorption as it shows higher rate of CO₂ adsorption at room temperature. In conventional amine processes, a comparatively high energy penalty is required, whereas a novel class of metal-organic framework by the combination of amine solvent have improve the potential of adsorption process and also the efficiency of separation. Amine-functionalized MOFs become more fascinated due to strong interaction between carbon dioxide and amine-functionalized MOF. A renewable green γCD-MOF was synthesized by using vapor diffusion method. Post-synthetic modification of γCD-MOF was done with piperazine and analyzed to expose its crystalline structure, morphology, and porous structure. The main aim of this paper is to enhance the CO₂ adsorption by functionalization of inexpensive, green, nanoporous γCD-MOF and also to highlight the effects of amine-based functionalization towards potential application. Gravimetric CO₂ adsorption isotherms for γCD-MOF, pip-γCD-MOF are reported up to 60 °C and found to follow a pseudo-second-order reaction. The pip-γCD-MOF confirms comparatively increased rapid adsorption rate of CO₂ than that of γCD-MOF and desorption of CO₂, and need less energy for regeneration. These results are the complete evidence of piperazine as an efficient amine group for increasing the CO₂ adsorption uptake capacity.