Synergistic Effects between SO2 and HCOOH on α‑Fe2O3

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Vol. 117; no. 19; pp. 3972 - 3979
• Main Authors: Wu, Ling-Yan, Tong, Sheng-Rui, Zhou, Li, Wang, Wei-Gang, Ge, Mao-Fa
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 16.05.2013
• Subjects: Adsorption; Aerosols; Air Pollutants - chemistry; Atmosphere - chemistry; Catalysis; Chemistry; Exact sciences and technology; Ferric Compounds - chemistry; Formates - chemistry; Kinetics; Kinetics and mechanisms; Organic chemistry; Reactivity and mechanisms; Spectroscopy, Fourier Transform Infrared; Sulfates - chemistry; Sulfur Dioxide - chemistry; Correlation; Catalytic reaction; Fourier transform spectroscopy; Fourier transformation; Iron oxide; Coadsorption; Carbon dioxide; Steric hindrance; Sulfur dioxide; Infrared spectrometry; Pollutant; Inorganic anion; Atmospheric chemistry; Organic sulfate; Aerosols; Carboxylate; Formate; Gas phase; Triatomic molecule; Gallium selenides; Heterogeneous reaction
• ISSN: 1089-5639; 1520-5215; 1520-5215
• DOI: 10.1021/jp400195f

Heterogeneous reactions on mineral aerosols remain an important subject in atmospheric chemistry because of their role in altering the properties of particles and the budget of trace gases. Yet, the role of coadsorption of trace gases onto mineral aerosols and potential synergistic effects are largely uncertain, especially synergistic effects between inorganic and organic gas-phase pollutants. In this study, synergistic effects between HCOOH and SO2 were investigated for the first time using in situ diffuse-reflectance infrared Fourier transform spectroscopy (DRIFTS). It was found that the heterogeneous reaction of HCOOH is hindered significantly by coexisting SO2. The total amount of formate decreased, whereas the total amount of sulfate was not affected during coadsorption on the surface of α-Fe2O3. Futhermore, part of the formate on the surface was catalytically decomposed to CO2 by α-Fe2O3 with the help of SO2. These results suggest a possible mechanism for the observed correlations between sulfate and carboxylate in the atmosphere.