Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
School of Metallurgy, Northeastern University, Shenyang, 110819, China.
Environ Sci Pollut Res Int. 2017 Sep;24(26):21248-21255. doi: 10.1007/s11356-017-9766-y. Epub 2017 Jul 22.
The influences of relative humidity (RH) on the heterogeneous reaction of NO with soot were investigated by a coated wall flow tube reactor at ambient pressure. The initial uptake coefficient (γ ) of NO showed a significant decrease with increasing RH from 7 to 70%. The γ on "fuel-rich" and "fuel-lean" soot at RH = 7% was (2.59 ± 0.20) × 10 and (5.92 ± 0.34) × 10, respectively, and it decreased to (5.49 ± 0.83) × 10 and (7.16 ± 0.73) × 10 at RH = 70%, respectively. Nevertheless, the HONO yields were almost independent of RH, with average values of (72 ± 3)% for the fuel-rich soot and (60 ± 2)% for the fuel-lean soot. The Langmuir-Hinshelwood mechanism was used to demonstrate the negative role of RH in the heterogeneous uptake of NO on soot. The species containing nitrogen formed on soot can undergo hydrolysis to produce carboxylic species or alcohols at high RH, accompanied by the release of little gas-phase HONO and NO.
在常压下，通过涂壁式流动管反应器研究了相对湿度 (RH) 对 NO 与烟尘非均相反应的影响。NO 的初始摄取系数 (γ) 随 RH 从 7%增加到 70%而显著降低。在 RH = 7%时，“富燃料”和“贫燃料”烟尘上的 γ 值分别为 (2.59 ± 0.20)×10 和 (5.92 ± 0.34)×10，而在 RH = 70%时，分别降低至 (5.49 ± 0.83)×10 和 (7.16 ± 0.73)×10。然而，HONO 的产率几乎与 RH 无关，富燃料烟尘的平均产率为 (72 ± 3)%，贫燃料烟尘的平均产率为 (60 ± 2)%。朗缪尔-欣谢尔伍德机制被用来证明 RH 在烟尘上的 NO 非均相摄取中的负面作用。烟尘上形成的含氮物种在高 RH 条件下会发生水解，生成羧酸或醇，同时释放少量气相 HONO 和 NO。
