Yang Qun, Cheng Xiyue, Xu Qian, Deng Shuiquan
Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Stricture of Matter, Chinese Academy of Sciences, Fuzhou 350002, China.
College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007, China.
Molecules. 2025 May 6;30(9):2067. doi: 10.3390/molecules30092067.
Carbon isotopes, particularly C, are critical for applications in food authentication, biomedical diagnostics, and metabolic research; however, their efficient separation remains challenging due to their low natural abundance. This study investigates the adsorption behavior of CO and CO on various low-index α-AlO surfaces as a strategy for isotope separation. Density functional theory (DFT) calculations with D3 (BJ) dispersion corrections were employed to optimize surface models for five representative α-AlO facets. Nine adsorption configurations were systematically evaluated by optimizing geometric structures, computing adsorption enthalpies with zero-point energy corrections, and performing Bader charge and charge density difference analyses to elucidate interfacial interactions. The results reveal that CO preferentially adsorbs in a vertical configuration via its carbon end at Al sites, with the (0001) surface exhibiting the lowest surface energy and most favorable adsorption characteristics. Furthermore, we found that facets with lower surface energy not only facilitate stronger CO adsorption but also demonstrate pronounced adsorption enthalpy differences between CO and CO, driven by vibrational zero-point energy disparities. These findings highlight the potential of low adsorption enthalpy surfaces, particularly (0001), (011¯2), and (112¯0), for enhancing isotope separation efficiency, providing valuable insights for the design of advanced separation materials.
碳同位素，特别是碳 - 13，在食品认证、生物医学诊断和代谢研究中具有重要应用；然而，由于它们的天然丰度低，其有效分离仍然具有挑战性。本研究调查了一氧化碳（CO）和二氧化碳（CO₂）在各种低指数α - Al₂O₃表面上的吸附行为，以此作为同位素分离的一种策略。采用带有D3（BJ）色散校正的密度泛函理论（DFT）计算来优化五个代表性α - Al₂O₃晶面的表面模型。通过优化几何结构、计算零点能校正后的吸附焓以及进行巴德电荷和电荷密度差分析来系统评估九种吸附构型，以阐明界面相互作用。结果表明，CO优先通过其碳端以垂直构型吸附在铝位点上，（0001）表面表现出最低的表面能和最有利的吸附特性。此外，我们发现表面能较低的晶面不仅有利于更强的CO吸附，而且由于振动零点能差异，在CO和CO₂之间表现出明显的吸附焓差异。这些发现突出了低吸附焓表面，特别是（0001）、（011̅2）和（112̅0）晶面在提高同位素分离效率方面的潜力，为先进分离材料的设计提供了有价值的见解。
