(253l) First Principles Computational Study on Adsorption of Organic Methyl Iodide in Triethylenediamine Impregnated Activated Carbon

Authors: 
Chun, H., Yonsei University
Han, B., Yonsei University
First Principles Computational Study on Adsorption of Organic Methyl Iodide in Triethylenediamine Impregnated Activated Carbon

Hoje Chun1, Byungchan Han2*

1Integrated Science and Engineering Division, Yonsei University, Seoul, 03722, Republic of Korea

2Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 03722, Republic of Korea

We study removal of gas-phase organic iodine (CH3I), which is one of the toxic chemical generated in nuclear power plant operation or accidents, via adsorption in triethylenediamine (TEDA) impregnated activated carbon (AC). We apply first principles density functional theory (DFT) calculations to understand how experimentally observed quaternary ammonium salts form in the surface. It is propose that the adsorption energy of a CH3I shows substantial heterogeneity as function of varying the adsorption sites, porosity and H2O environment. Most importantly, it is clearly shown by first principles calculated free energy diagrams for the adsorption processes that TEDA not only helps in reducing the activation barrier of the dissociation of CH3I but also attracts H2O molecules freeing the porous AC surface from poisoning by humidity and enhancing removal efficiency of the CH3I. Our computational study enables to unveil detailed chemical process and thus, can open new ways to design highly functional AC in removing environmentally and biologically hazardous materials.