Unravelling the surface physical and chemical properties, especially the surface activity of Pu-oxides (PuO₂, α-Pu₂O₃) toward molecules, is essential to the long-term storage and surface reaction of Pu. Within DFT+U-D3 scheme, we systematically investigate the adsorption behaviors of H₂O and CO₂ on α-Pu₂O₃(111) surface, and clarify the different chemical activity of α-Pu₂O₃(111) surface from PuO₂(111), which is due to the distinct coordination and bonding property of the top-layer Pu. There are five- and six-coordinated Pu (Pu_5c, Pu_6c) on α-Pu₂O₃(111) surface, among which Pu_5c is more reactive with lower work-function than Pu_6c. Interestingly, H₂O and CO₂ present the preferential adsorption at the Pu_5c sites rather than Pu_6c, namely, the site-selective adsorption. H₂O tends to dissociate spontaneously and adsorb in cluster as with the coverages increase, while CO₂ keeps the molecular state adsorption. The calculated phase diagram and isotherm indicate that the adsorption quantity and stability of H₂O are higher than CO₂ at the same (T, P) condition, and CO₂ can achieve the multilayer adsorption at high pressure (P_CO2). This work reveals the chemical heterogeneity of α-Pu₂O₃(111) surface and the selective adsorption mechanism of active molecules, which clearly depicts the interactions between environment gaseous and Pu-oxide surfaces.

解开的表面的物理和化学性质，尤其是普氧化物的表面活性（的PuO ₂，α-莆₂ ö ₃）朝向分子，是必不可少的浦的长期存储和表面反应。内DFT + ü -D3方案中，我们系统地研究H的吸附行为₂ O和CO ₂的α-莆₂ ö ₃（111）面，并澄清的不同的化学活性α-莆₂ ö ₃（111）从表面PuO ₂（111），这归因于顶层Pu的独特的配位和键合特性。有五坐标和六坐标的Pu（Pu _5c浦_6C上α-浦）₂ ö ₃（111）表面，其中溥_5C是具有较低功函数比普更具反应性_6c中。有趣的是，H ₂ O和CO ₂在Pu _5c位点而不是在Pu _6c位点表现出优先吸附，_即位点选择性吸附。随着覆盖率的增加，H ₂ O倾向于自发解离并成簇吸附，而CO _2则保持分子态吸附。计算出的相图和等温线表明，H ₂ O的吸附量和稳定性均高于CO _2。在相同的（T，P）条件下，CO ₂可以在高压（P _CO2）下实现多层吸附。这项工作揭示α-莆的化学异质₂ ö ₃（111）面和活性分子的选择性吸附机构，它清楚地描述了环境的气态和钚氧化物表面之间的相互作用。