The density functional theory (DFT) calculations were conducted to study the adsorption and diffusion of oxygen on Ta(100) and Ta(110) with and without the substitution of rare earth (RE, RE= Y, Ce and La) in the surface layer, which aims to reveal the possible RE-catalyzed oxidation mechanism of those two surfaces. The calculated results show that the oxygen atoms are preferentially adsorbed on the hollow site of clean Ta(100) and Ta(110). The RE doping in the subsurface layer weakens the adsorption strength of oxygen on Ta(110), while it has a negligible influence on that on Ta(100). In contrast, the substitution of RE in the surface layer can enhance the adsorption ability of oxygen atom on the two surfaces, which is also proved by the analysis of Bader charge and electron localization function. Additionally, the oxygen atoms are predicted to preferentially occupy the octahedral site in the subsurface of Ta slabs with and without RE doping. The investigations of oxygen diffusion behaviors indicate that the RE, especially for La, doping in the surface layer decrease the energy barrier of oxygen penetration into Ta surface, and thus catalyze the oxidation process of Ta slabs. Those results could help to provide a fundamental basis for comprehending the oxidation mechanism of Ta surface with RE doping.

进行密度泛函理论 (DFT) 计算以研究氧在 Ta(100) 和 Ta(110) 上的吸附和扩散，无论是否在表面取代稀土（RE、RE= Y、Ce 和 La）层，旨在揭示这两个表面可能的 RE 催化氧化机制。计算结果表明，氧原子优先吸附在干净的Ta(100)和Ta(110)的中空部位。亚表层稀土掺杂削弱了氧对Ta(110)的吸附强度，而对Ta(100)的吸附影响可以忽略不计。相比之下，在表面层中RE的取代可以增强氧原子在两个表面上的吸附能力，这也被Bader电荷和电子定位函数的分析所证明。此外，预测氧原子优先占据有和没有稀土掺杂的钽板次表面的八面体位置。对氧扩散行为的研究表明，稀土，尤其是La，在表层中的掺杂降低了氧渗透到Ta表面的能垒，从而催化了Ta板的氧化过程。这些结果有助于为理解稀土掺杂Ta表面的氧化机制提供基本依据。