Density functional theory study of CO2 capture with transition metal oxides and hydroxides

作者：Zhang, Bo; Duan, Yuhua; Johnson, Karl^*

来源：Journal of Chemical Physics, 2012, 136(6): 064516.

DOI：10.1063/1.3684901

• ZEOLITIC IMIDAZOLATE FRAMEWORKS
• CHEMICAL-LOOPING COMBUSTION
• INITIO MOLECULAR-DYNAMICS
• TOTAL-ENERGY CALCULATIONS
• CARBON-DIOXIDE CAPTURE
• ELECTRONIC-STRUCTURE
• ADSORPTION
• ABSORPTION
• SORBENTS
• SURFACES

We have used density functional theory (DFT) employing several different exchange-correlation functionals (PW91, PBE, PBEsol, TPSS, and revTPSS) coupled with lattice dynamics calculations to compute the thermodynamics of CO2 absorption/desorption reactions for selected transition metal oxides, (TMO), and hydroxides, TM(OH)(2), where TM = Mn, Ni, Zn, and Cd. The van't Hoff plots, which describe the reaction equilibrium as a function of the partial pressures of CO2 and H2O as well as temperature, were computed from DFT total energies, complemented by the free energy contribution of solids and gases from lattice dynamics and statistical mechanics, respectively. We find that the PBEsol functional calculations are generally in better agreement with experimental phase equilibrium data compared with the other functionals we tested. In contrast, the formation enthalpies of the compounds are better computed with the TPSS and revTPSS functionals. The PBEsol functional gives better equilibrium properties due to a partial cancellation of errors in the enthalpies of formation. We have identified all CO2 capture reactions that lie on the Gibbs free energy convex hull as a function of temperature and the partial pressures of CO2 and H2O for all TMO and TM(OH)(2) systems studied here.

• 出版日期2012-2-14