Synergistic Effect between NO2 and SO2 in Their Adsorption and Reaction on γ-Alumina

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• 作者：Qingxin Ma ; Yongchun Liu ; Hong He
• 刊名：Journal of Physical Chemistry A
• 出版年：2008
• 出版时间：July 24, 2008
• 年：2008
• 卷：112
• 期：29
• 页码：6630-6635
• 全文大小：236K
• 年卷期：v.112,no.29(July 24, 2008)
• ISSN：1520-5215

文摘

Field measurements showed that there exists a correlation between nitrate and sulfate on mineral dust. In this work, the synergistic mechanism of adsorption and reaction between SO₂ and NO₂ on gamma-alumina was studied using in situ diffusion reflectance infrared Fourier spectroscopy (in situ DRIFTS) and temperature programmed desorption (TPD). The results revealed that the reaction pathway of NO₂ adsorbed on alumina was altered in the presence of SO₂. In the absence of SO₂, nitrite was found to be an intermediate in the oxidation of NO₂ to surface nitrate species. However, in the presence of SO₂, the formation of nitrite was inhibited and a new intermediate, dinitrogen tetraoxide (N₂O₄), was observed. On the other hand, surface tetravalent sulfur species S(IV), including bisulfite and sulfite, were oxidized to sulfate in air condition when NO₂ was present. The atmospheric implication of this synergistic effect was also discussed.