Premium
Heterogeneous chemistry of NO 2 on mineral oxide particles: Spectroscopic evidence for oxide‐coordinated and water‐solvated surface nitrate
Author(s) -
Miller T. M.,
Grassian V. H.
Publication year - 1998
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1998gl900011
Subject(s) - nitrate , oxide , inorganic chemistry , chemistry , oxide minerals , nitrite , adsorption , mineral , surface water , environmental chemistry , chemical reaction , environmental engineering , organic chemistry , engineering
In this study, transmission FT‐IR and diffuse reflectance UV‐vis spectroscopies were used to probe the heterogeneous chemistry of gaseous nitrogen dioxide on mineral oxide particles. In particular, the role of pre‐ and post‐adsorbed water on the heterogeneous chemistry of NO 2 on Al 2 O 3 and TiO 2 was investigated. At 298 K, NO 2 reacts with the surface of these mineral oxides to form surface nitrite and nitrate. The spectroscopic data show that two distinct types of surface nitrate exist, oxide‐coordinated and water‐solvated nitrate. The relative amounts of oxide‐coordinated and water‐solvated nitrate are dependent on the coverage of adsorbed water on the surface of the mineral oxide particle. The importance of this water layer in the heterogeneous atmospheric chemistry of mineral oxide aerosol is discussed.