通过第一原则模拟,对大气中硫酸形成的机械洞察力
Manar Al-Kharusi1, Ali Kachmar1, Nidhal Sulaiman1
1College of Science, Department of Physics, Sultan Qaboos University, P.O. Box 36, P.C. 123 Muscat, Oman.
The journal of physical chemistry letters
|September 15, 2025
概括
硫酸的形成对大气核形成至关重要. 密度函数理论计算揭示了关键反应路径和能量障碍,确定DC-r2SCAN和r2SCAN作为高效的计算方法.
科学领域:
- 大气化学 大气化学
- 计算化学计算化学
- 化学物理 化学物理
背景情况:
- 硫酸 (H2SO4) 在大气核和云凝聚核 (CCN) 的形成中起着至关重要的作用.
- 了解H2SO4的形成途径对于大气建模和预测气候影响至关重要.
研究的目的:
- 通过密度函数理论 (DFT) 来研究二氧化硫 (SO2) 中的硫酸 (H2SO4) 的形成.
- 计算H2SO4形成中的三个关键反应的反应和激活能量.
- 评估各种DFT函数的性能,包括r2SCAN和DC-r2SCAN,用于描述这些大气反应.
主要方法:
- 使用密度函数理论 (DFT) 的计算.
- 使用了几种DFT风味:PBE,r2SCAN,DC-r2SCAN,CAM-B3LYP,以及PBE0.0等.
- 对SO2氧化,HOSO2+O2反应和SO3水解进行了反应和激活能量的计算.
主要成果:
- 反应R1 (SO2氧化) 的反应能量为-23.845 kcal/mol,激活能量为-0.628 kcal/mol,使用DC-r2SCAN.
- 反应R2 (HOSO2 + O2) 在CAM-B3LYP/6-31G**水平上表现出一个小但显著的激活屏障1.225 kcal/mol,与之前的假设相反.
- 反应R3 (SO3水解) 使用r2SCAN/TZV2P.产生了23.218 kcal/mol的反应能量和5.648 kcal/mol的激活能量.
结论:
- 该研究强调了像r2SCAN和DC-r2SCAN这样的计算方法对于准确描述硫酸形成的重要性.
- 这些DFT函数为大气化学研究的高级方法提供了计算效率高的替代方案.
- 这些发现为改善与核和云形成有关的大气模型提供了有价值的数据.
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