Heterogeneous Reactions of Methylglyoxal in Acidic Media: Implications for Secondary Organic Aerosol Formation
详细信息 查看全文
- 作者：Jun Zhao ; Nicholas P. Levitt ; Renyi Zhang ; Jianmin Chen
- 刊名：Environmental Science & Technology
- 出版年：2006
- 出版时间：December 15, 2006
- 年：2006
- 卷：40
- 期：24
- 页码：7682 - 7687
- 全文大小：135K
- 年卷期：v.40,no.24(December 15, 2006)
- ISSN：1520-5851
文摘
Recent environmental chamber studies have suggestedthat acid-catalyzed particle-phase reactions of organiccarbonyls contribute to the formation of secondary organicaerosol (SOA). We report the first measurements ofuptake of methylglyoxal on liquid H2SO4 over the temperaturerange of 250-298 K and acidic range of 55-85 wt %.From the time-dependent uptake the effective Henry's lawsolubility constant (H*) was determined. Heterogeneousreactions of methylglyoxal are shown to decrease with acidityand involve negligible formation of sulfate esters. Hydrationand polymerization likely explain the measured uptakeof methylglyoxal on H2SO4 and the measurements do notsupport an acid-catalyzed uptake of methylglyoxal. The resultsimply that heterogeneous reactions of methylglyoxalcontribute to organic aerosol formation in less acidic mediaand hydration and polymerization of methylglyoxal in theatmospheric aerosol-phase are dependent on thehygroscopicity, rather than the acidity of the aerosols.