An Ab Initio Molecular Dynamics Study of the Hydrolysis Reaction of Sulfur Trioxide Catalyzed by a Formic Acid or Water Molecule.,The Journal of Physical Chemistry A

当前位置： X-MOL 学术 › J. Phys. Chem. A › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

An Ab Initio Molecular Dynamics Study of the Hydrolysis Reaction of Sulfur Trioxide Catalyzed by a Formic Acid or Water Molecule.
The Journal of Physical Chemistry A ( IF 2.7 ) Pub Date : 2020-03-03 , DOI: 10.1021/acs.jpca.9b11954
Pinja Kangas ₁ , Vesa Hänninen ₁ , Lauri Halonen ₁

Affiliation

Ab initio molecular dynamics (AIMD) calculations have been performed to investigate the role of dynamical and steric effects in formic acid (FA) or H2O-catalyzed gas phase hydrolysis of SO3 to form sulfuric acid. This was done by colliding FA or H2O with the SO3-H2O complex and the water dimer with the SO3 molecule and analyzing the outcomes of 230 AIMD trajectories. Our calculations show that, within simulation times used, sulfuric acid is formed in 5% of FA collisions but is not produced when H2O collides with the SO3-H2O complex or when the water dimer collides with the SO3 molecule. We also find that FA collisions have about 2 times higher probability to form the prereactive complex than H2O collisions. Moreover, our simulations show that the SO3-H2O-FA prereactive complex is more stable in time than the SO3-H2O-H2O prereactive complex. These findings indicate that the FA-catalyzed mechanism is favored over the H2O one when looking from the steric and dynamic effect point of view. Additionally, AIMD simulations starting from the optimized structure of the SO3-H2O-FA prereactive complex have been computed to qualitatively estimate the rate of the sulfuric acid formation. Collisional energy has been observed to promote sulfuric acid formation more effectively than thermal excitation.

中文翻译：

甲酸或水分子催化的三氧化硫水解反应的从头算分子动力学研究。

已进行了从头算分子动力学（AIMD）计算，以研究动力学和空间效应在甲酸（FA）或H2O催化的SO3气相水解形成硫酸中的作用。这是通过将FA或H2O与SO3-H2O配合物碰撞并将水二聚体与SO3分子碰撞并分析230条AIMD轨迹的结果来完成的。我们的计算表明，在所用的模拟时间内，硫酸在5％的FA碰撞中形成，但当H2O与SO3-H2O配合物碰撞或水二聚体与SO3分子碰撞时不会生成硫酸。我们还发现，FA碰撞形成预反应复合物的概率比H2O碰撞高2倍。此外，我们的模拟表明，SO3-H2O-FA预反应复合物的时间比SO3-H2O-H2O预反应复合物的时间更稳定。这些发现表明，从空间和动态效应的角度看，FA催化的机理优于H2O的机理。此外，已计算出从SO3-H2O-FA预反应性配合物的优化结构开始的AIMD模拟，以定性估算硫酸形成的速率。已经观察到碰撞能比热激发更有效地促进硫酸的形成。

更新日期：2020-03-03

点击分享查看原文

点击收藏

阅读更多本刊最新论文