Heterogeneous Uptake of Gas-Phase Acetic Acid on the Surface of alpha-Al2O3 Particles: Temperature Effects
Heterogeneous Uptake of Gas-Phase Acetic Acid on the Surface of alpha-Al2O3 Particles: Temperature Effects
复制标题
α-Al2O3 颗粒表面气相乙酸的非均相吸收：温度影响
DOI：
10.1002/asia.201600402
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发表时间：
2016
影响因子：
4.1
通讯作者：
Ge Maofa
中科院分区：
文献类型：
--
作者：
Hou Siqi;Tong Shengrui;Zhang Ying;Tan Fang;Guo Yucong;Ge Maofa
非均相反应被认为在灰霾的形成中起着重要的作用，特别是在冬季，这表明温度可能会影响有机气溶胶的非均相形成。以地球大气中含量最丰富的羧酸--乙酸为研究对象，在248~298 K温度范围内，研究了温度对其与α-Al2O3非均相反应的影响。 产物的原位DRIFTS，这表明，降低温度减缓乙酸的形成，但促进结晶乙酸的形成。 此外，低温促进了与室温下不同的反应机理。由于在低温下形成链状结构，结晶乙酸分子覆盖在α-Al2O3的表面活性位点上，从而抑制乙酸盐的形成。然而，结晶乙酸与α-Al2O3本身以顺序方式反应。此外，反应吸收系数，活化能，和乙酸在不同温度下的寿命进行了研究。
Heterogeneous reactions are thought to play a significant role in the formation of haze, especially in wintertime, which suggests that temperature may affect the heterogeneous formation of organic aerosols. As the most‐abundant carboxylic acid in the Earth′s atmosphere, we chose acetic acid to study the effect of temperature on its heterogeneous reaction with α‐Al2O3between 248 and 298 K. The products were characterized by in situ DRIFTS, which indicated that lowering the temperature slowed the formation of acetate, but promoted the formation of crystalline acetic acid. Moreover, low temperatures promoted a different reaction mechanism to that at room temperature. Owing to the formation of chain structures at low temperatures, crystalline acetic acid molecules covered the surface active sites on α‐Al2O3, thereby inhibiting the formation of acetate. However, crystalline acetic acid reacted with α‐Al2O3itself in a sequential manner. Furthermore, the reactive uptake coefficients, active energies, and acetic acid lifetimes at different temperatures were investigated.