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Updated: Aug 16, 2026

Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
Synergistic enhancement and competitive mechanisms of multiple amide molecules on atmospheric sulfuric acid
Liang Fan1, Yi Shen2, Xintong Zhang1,3
1State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
Abstract:
Amides, especially multiple amide molecules, play a critical yet under-resolved role in new particle formation (NPF), which in turn affects aerosol formation. This study systematically evaluates the potential and mechanisms of multiple amide molecules on promoting SA-NH3 nucleation, including methylacetamide (MAA) and methylpropionamide (MPA). Results demonstrate that clusters (SA)1·(MPA)1 and (SA)1·(MAA)1 display excellent thermodynamic and kinetic stability compared with (SA)1·(NH3)1, even (SA)1·(DMA)1, suggesting the nucleation potential of MPA and MAA. Crucially, a profound synergistic enhancement of MPA and MAA was identified in ternary SA-NH3-MPA/MAA and quaternary SA-NH3-MPA-MAA nucleation systems, where the synergistic enhancement strength exceeds individual enhancement by an order of magnitude, especially at lower SA concentrations and temperatures. Moreover, a competitive mechanism was identified where MPA replaces NH3 and MAA replaces MPA. The study highlights the synergistic enhancement of multiple alkaline precursors on NPF, offering theoretical data and mechanism support for the improvement of global nucleation models.
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