Conversion of gaseous nitrogen dioxide to nitrate and nitrite on aqueous surfactants
Conversion of gaseous nitrogen dioxide to nitrate and nitrite on aqueous surfactants
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DOI：
10.1039/c0cp01497d
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发表时间：
2011-01-01
影响因子：
3.3
通讯作者：
Colussi, Agustin J.
中科院分区：
文献类型：
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作者：
Kinugawa, Takashi;Enami, Shinichi;Colussi, Agustin J.
气态NO2在水表面(2NO2+H2O->；HONO+NO3-+H+)(R1)的水解歧化反应一直被认为在对流层化学中起着关键的作用，尽管这是无法量化的。我们最近在由在线电喷雾质谱仪监测的水微喷流上进行的实验中发现，阴离子显著加速了(R1)的形成。这一发现使我们解释了以前实验室结果中未解决的差异，并建议在现实的环境条件下，(R1)应该受到一直存在的表面活性剂的影响。在这里，我们报告了阳离子表面活性剂显著促进NO2(G)的吸收，黄腐酸(FA，一种天然多元羧酸)和阴离子表面活性剂对NO2(G)的吸收有微弱的抑制作用，而正辛醇没有影响。表面活性剂似乎通过与带电头基的静电相互作用来调节界面阴离子覆盖。结果表明，在典型大气条件下，(R1)可能是NO2(G)全天非均相转化为HONO的主要机理。在白天，NO2在空气烟尘上光诱导还原为HONO的作用可能是有限的。
The hydrolytic disproportionation of gaseous NO2 on water's surface (2 NO2 + H2O -> HONO + NO3- + H+) (R1) has long been deemed to play a key, albeit unquantifiable role in tropospheric chemistry. We recently found that (R1) is dramatically accelerated by anions in experiments performed on aqueous microjets monitored by online electrospray mass spectrometry. This finding let us rationalize unresolved discrepancies among previous laboratory results and suggested that under realistic environmental conditions (R1) should be affected by everpresent surfactants. Herein, we report that NO2(g) uptake is significantly enhanced by cationic surfactants, weakly inhibited by fulvic acid (FA, a natural polycarboxylic acid) and anionic surfactants, and unaffected by 1-octanol. Surfactants appear to modulate interfacial anion coverage via electrostatic interactions with charged headgroups. We show that (R1) should be the dominant mechanism for the heterogeneous conversion of NO2(g) to HONO under typical atmospheric conditions throughout the day. The photoinduced reduction of NO2 into HONO on airborne soot might play a limited role during daytime.