结合密度泛函理论框架内的周期性平板模型,运用第一性原理计算方法研究了CO2在δ-Pu(100)表面的吸附行为.结果 表明,CO2分子以C端向下和C-Pu、O-Pu多键结合的方式吸附在δ-Pu(100)表面.吸附类型属于强化学吸附,最稳定的吸附构型是H1-C4O4,此时吸附能为-6.430 eV,吸附稳定性顺序为穴位＞桥位＞顶位.CO2分子主要和表面Pu原子反应,而与其它3层Pu原子的反应较弱.更多的电子向CO22πu轨道转移有利于C-O键的弯曲和活化.此外,CO2分子和Pu原子之间的化学键主要是离子态,反应机理是CO2的C 2s、C2p、O2s和O2p轨道与Pu 6p、Pu 6d、Pu 5f轨道发生了重叠杂化作用,产生了新的键结构.H1-C4O4构型的功函数变化最小,表明其它电子容易从该构型表面逃逸,且需要的能量最小.“,”A first-principles calculation was applied to study the adsorption behavior of CO2 on δ-Pu(100) surface using a slab model within the framework of density functional theory.Results demonstrate that CO2 molecules are adsorbed on δ-Pu(100) surface at C-terminated bent state by multi-bond binding of C-Pu and O-Pu.The adsorption type belongs to strong chemical adsorption and the most stable adsorption configuration is H1-C4O4with the adsorption energy of-6.430 eV.The adsorption stability order is hollow site>bridge site＞top site.CO2 molecule mainly interacts with Pu surface atoms,while the interaction with other three Pu atoms is weak.The transfer of more electrons to the CO22πu orbital is beneficial to the bending and activation of C-O bonds.Moreover,the chemical bonding between Pu atoms and CO2 molecule is mainly ionic state and the reaction mechanism is that the C 2s,C 2p,O 2s and O 2p orbitals of CO2 molecule hybrid with Pu 6p,Pu 6d and Pu 5f orbitals,resulting in a new bond structure.The work function of the H1-C4O4 site changes the least,indicating that other electrons readily escape from the metal surface and the required energy is the smallest.