In this study, to understand the oxidation mechanism of transmission pipeline surface (Fe) in supercritical CO₂ (SCO₂), the microstructure of Fe/SCO₂ system was established, and molecular dynamics (MD) simulations were performed using reactive force field (ReaxFF), the oxidation mechanism was revealed at nanoscale. The results indicated that the initial oxidation of Fe was induced by the absorption of SCO₂ molecules near the iron surface. The dynamic evolution of atom behavior and charge transfer were clarified and observed. It was found that the surface iron atoms lose more electrons than the inner iron atoms, the delamination of the simulated system was demonstrated by us, and the carbon deposition in the desquamation area was also observed. It is demonstrated that a low area density can contribute to the occurrence of oxidation reaction. The oxidation reaction rate is rapid at initial stage, and it decreases with the increase of oxidation reaction time.

本研究为了解超临界CO ₂ (SCO ₂ )中输送管道表面(Fe)的氧化机理，建立了Fe/SCO ₂体系的微观结构，并利用反应力场进行了分子动力学(MD)模拟( ReaxFF），在纳米尺度上揭示了氧化机制。结果表明，Fe的初始氧化是由SCO _{2的吸收引起的。}铁表面附近的分子。阐明并观察了原子行为和电荷转移的动态演化。发现表面铁原子比内部铁原子失去更多的电子，我们演示了模拟系统的分层，并且还观察到了脱屑区域的积碳。已证明低的面密度可有助于氧化反应的发生。初期氧化反应速度较快，随着氧化反应时间的增加而降低。