Does HNO3 dissociate on gas-phase ice nanoparticles?

0573653 - ÚFCH JH 2024 RIV GB eng J - Journal Article
Khramchenkova, A. - Pysanenko, Andriy - Ďurana, Jozef - Kocábková, Barbora - Fárník, Michal - Lengyel, J.
Does HNO3 dissociate on gas-phase ice nanoparticles?
Physical Chemistry Chemical Physics. Roč. 25, č. 32 (2023), s. 21154-21161. ISSN 1463-9076. E-ISSN 1463-9084
R&D Projects: GA ČR(CZ) GA21-07062S
Institutional support: RVO:61388955
Keywords : molecular dynamics * HNO3 * nanoparticles
OECD category: Physical chemistry
Impact factor: 3.3, year: 2022
Method of publishing: Open access

We investigated the dissociation of nitric acid on large water clusters (H2O)N, [N with combining macron] ≈ 30–500, i.e., ice nanoparticles with diameters of 1–3 nm, in a molecular beam. The (H2O)N clusters were doped with single HNO3 molecules in a pickup cell and probed by mass spectrometry after a low-energy (1.5–15 eV) electron attachment. The negative ion mass spectra provided direct evidence for HNO3 dissociation with the formation of NO3−⋯H3O+ ion pairs, but over half of the observed cluster ions originated from non-dissociated HNO3 molecules. This behavior is in contrast with the complete dissociation of nitric acid on amorphous ice surfaces above 100 K. Thus, the proton transfer is significantly suppressed on nanometer-sized particles compared to macroscopic ice surfaces. This can have considerable implications for heterogeneous processes on atmospheric ice particles.

Permanent Link: https://hdl.handle.net/11104/0344043