摘要
运用广义梯度密度泛函理论方法(density functional theory,DFT),结合周期性平板模型,研究了CO2在La2O3(011)表面的吸附和活化,计算了CO2吸附的吸附能和Mulliken电荷数。结果表明,CO2在La2O3(011)表面吸附形成6种平衡构型,分别为CO2-η1、CO2-η2、CO2-η3a、CO2-η3b、CO2-η3c和CO2-rec。其中,CO2-η1为物理吸附,其余5种为化学吸附。在化学吸附构型中,CO2从表面获得电子,其结构发生弯曲,C—O键被拉长,形成CO2σ-活化分子;CO2在与表面成键过程中,C原子失去电子,而O原子得到电子,这与CO2在金属表面的得失电子情况是不同的。
Based on density functional theory in the generalized gradient approximation, together with periodic slab model, adsorption and activation of CO2 on La2O3 （011） surface had been studied, of which the adsorption energy and Mulliken charge were calculated too. Results showed that six equilibrium geometries, a physisorption structure （ 011-η1 ）, and five chemical adsorption structures （ CO2-η2 ,CO2-η3a,CO2-η3b,CO2-η3c and CO2-rec） were obtained. The CO2 obtained electron from the surface and formed activation molecular CO2^σ- in the chemical adsorption structures, CO2 molecule changed from linear structure to bended structure, and the C-O bond was lengthened. We also found that the C atom losed electrons and the O atoms obtained electrons in the adsorption process which was different from that of CO2 on the metal surface.
出处
《山西化工》
2011年第3期39-42,共4页
Shanxi Chemical Industry
