TY - JOUR
T1 - Adsorption and diffusion of carbon dioxide on ZIF-68
AU - Liu, Yang
AU - Kasik, Alexandra
AU - Linneen, Nick
AU - Liu, Jing
AU - Lin, Jerry
N1 - Funding Information:
The work was supported by the National Science Foundation (CBET-1160084) and National Natural Science Foundation of China ( 51376072 ). Yang Liu is grateful to China Scholarship Council for a fellowship to support his visit to ASU.
PY - 2014/10/18
Y1 - 2014/10/18
N2 - Zeolitic imidazolate framework ZIF-68 crystals of hexagonal rod shape were synthesized and used to study adsorption and diffusion of CO2 on ZIF-68. Grand canonical Monte Carlo (GCMC) calculations were performed to understand the CO2 adsorption sites on ZIF-68. Experimentally measured CO2 adsorption isotherms on ZIF-68 can be described by Langmuir adsorption isotherm. The molecular simulation results agree well with the experimental CO2 adsorption isotherms and heats of adsorption. The molecular simulation, coupled with the experimental isotherm data, has identified a new site between the faces of two converse nIM linkers, in addition to the two previously known sites for CO2 adsorption on ZIF-68. Diffusivity of CO2 on ZIF-68, obtained with a one-dimensional diffusion model, is in the range 1.1-1.6×10-7cm2/s in 298-328K, with an activation energy of 8.9kJ/mol. The experimentally measured CO2 diffusivity data of ZIF-68 is about one order of magnitude smaller than that obtained by molecular dynamic simulation.
AB - Zeolitic imidazolate framework ZIF-68 crystals of hexagonal rod shape were synthesized and used to study adsorption and diffusion of CO2 on ZIF-68. Grand canonical Monte Carlo (GCMC) calculations were performed to understand the CO2 adsorption sites on ZIF-68. Experimentally measured CO2 adsorption isotherms on ZIF-68 can be described by Langmuir adsorption isotherm. The molecular simulation results agree well with the experimental CO2 adsorption isotherms and heats of adsorption. The molecular simulation, coupled with the experimental isotherm data, has identified a new site between the faces of two converse nIM linkers, in addition to the two previously known sites for CO2 adsorption on ZIF-68. Diffusivity of CO2 on ZIF-68, obtained with a one-dimensional diffusion model, is in the range 1.1-1.6×10-7cm2/s in 298-328K, with an activation energy of 8.9kJ/mol. The experimentally measured CO2 diffusivity data of ZIF-68 is about one order of magnitude smaller than that obtained by molecular dynamic simulation.
KW - Diffusion
KW - Metal-organic framework
KW - Microporous materials
KW - Molecular simulation
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U2 - 10.1016/j.ces.2014.07.030
DO - 10.1016/j.ces.2014.07.030
M3 - Article
AN - SCOPUS:84905372553
VL - 118
SP - 32
EP - 40
JO - Chemical Engineering Science
JF - Chemical Engineering Science
SN - 0009-2509
ER -