Atomistic insights into heterogeneous reaction of formic acid on mineral oxide particles. (January 2022)

• Record Type: Journal Article
• Authors: Yuan, Shideng; Liu, Shasha; Du, Yingzhe; Wang, Xueyu; Zhang, Heng; Yuan, Shiling
• Is Part Of: Chemosphere. Volume 287:Part 4(2022)
• Publication Date: 2022-01
• Subjects: Atmospheric formic acid -- Mineral dust particles -- Theoretical study -- Heterogeneous reaction; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2021.132430
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The heterogeneous reaction between formic acid and mineral dust play an important role in tropospheric chemistry. However, the molecular mechanism on formic acid uptake on mineral dust is not yet to be fully understood. In our work, a comprehensive and multiscale theoretical study (include density functional theory, DFT calculations and reactive molecular dynamics, RMD simulations) has been provided to investigate this heterogeneous reaction at molecular level. The results of DFT calculations show that the SiO2 and TiO2 particles have a strong tendency to adsorb formic acid to its surface, and the attractive part of the binding energy was dominated by electrostatic component. RMD simulations show that the uptake of formic acid and water on TiO2 particles would modified TiO2 particles, which formed Ti–OH and Ti–OCHO on particle surface. Besides, the formic acid coordination surface modes were dominated by the monodentate formate mode rather than bidentate formate mode. The molecular level study is helpful for understanding the accumulation of formic acid on mineral dust particles and global balance of atmospheric formic acid. Graphical abstract: Image 1 Highlights: The uptake of HCOOH and H2 O onto TiO2 particles is easy to happen. The surface Ti atoms were oxidized after the reaction between HCOOH and TiO2 . With the increase of temperature, the heat released by the reaction also increased. The HCOOH uptake on TiO2 surface was suppressed with the increase of humidity.