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.