Adsorption and Dissociation of CO(2)on the alpha-U(001) Surface

作者：Li Gan^*; Luo Wen Hua; Chen Hu Chi

来源：Acta Physico - Chimica Sinica, 2011, 27(10): 2319-2325.

• Density functional theory
• alpha-U(001) surface
• Carbon dioxide
• Adsorption

The adsorption and dissociation of CO2 on the alpha-U(001) surface at 0.25 monolayer (ML) coverage was studied using density functional theory (DFT) within the generalized gradient approximation (GGA). Stable structures and corresponding energies of CO2 adsorbed on the alpha-U(001) surface were obtained while the transition state and corresponding energy barrier for CO2 dissociation was determined. We discussed the interaction mechanism between CO2 and the alpha-U(001) surface. We found that CO2 strongly chemisorbed onto the alpha-U(001) surface in a multi-bonding manner with adsorption energies of 1.24-1.67 eV and the degree of C - O bond activation depended on the degree of electron transfer from surface to the adsorbed CO. The interaction between the U atoms and the CO2 molecules mainly comes from the population of the CO2 2 pi(u) lowest unoccupied molecular orbital (LUMO) by U electrons with CO2 2 pi(u)/1 pi(g)/3 sigma(u)-U 6d orbital hybridization. The dissociative adsorption energies for the CO2 adsorbed on the hollow1 and hollow2 sites with three C - U bonds and six O - U bonds (H1-C3O6 and H-2-C3O6) are 3.15 and 3.13 eV, respectively. The corresponding dissociation barriers are 0.26 and 0.36 eV, which indicates that the dissociation of adsorbed CO2 into CO and O occurs easily.

• 出版日期2011-10
• 单位中国工程物理研究院