School of Resources & Environmental Engineering, Hefei University of Technology, Hefei 230009, People's Republic of China.
J Phys Chem A. 2010 Aug 19;114(32):8384-90. doi: 10.1021/jp104497d.
We have investigated the gas-phase UV photolysis of glycolaldehyde (HOCH(2)CHO) by laser photolysis combined with cavity ring-down spectroscopy. Absorption cross sections of glycolaldehyde in the 280-340 nm region were measured by cavity ring-down spectroscopy. The HCO + CH(2)OH and the OH + CH(2)CHO product channels following the photolysis of glycolaldehyde were directly examined. The average HCO quantum yields from the glycolaldehyde photolysis were 0.61 +/- 0.08, 0.59 +/- 0.05, 0.61 +/- 0.16, 0.66 +/- 0.09, 0.61 +/- 0.11, 0.65 +/- 0.05, 0.47 +/- 0.04, 0.52 +/- 0.09, and 0.45 +/- 0.05 at 280, 285, 290, 295, 300, 305, 308, 310, and 315 nm, where the error quoted (1sigma) represents experimental scatter. The average OH quantum yield from the photolysis of glycolaldehyde at 308 nm was 0.11 +/- 0.02, where the error quoted (1sigma) represents measurement uncertainty. End products such as CO, H(2)CO, (CHO)(2), CH(3)OH, HCOOH, and CO(2) were detected from the 308 nm photolysis of glycolaldehyde. The yields of CO, H(2)CO, (CHO)(2), CH(3)OH, and HCOOH were estimated. We also directly measured the rate constant for the reaction between the OH radical and glycolaldehyde. The rate constant obtained was (1.01 +/- 0.20) x 10(-11) cm(3) molecule(-1) s(-1), where the error quoted (1sigma) represents measurement uncertainty. Atmospheric implications of the results are discussed.
我们通过激光光解结合腔衰荡光谱研究了乙二醇醛（HOCH(2)CHO）的气相 UV 光解。通过腔衰荡光谱测量了乙二醇醛在 280-340nm 区域的吸收截面。直接检测了乙二醇醛光解后的 HCO + CH(2)OH 和 OH + CH(2)CHO 产物通道。乙二醇醛光解的平均 HCO 量子产率分别为 0.61 +/- 0.08、0.59 +/- 0.05、0.61 +/- 0.16、0.66 +/- 0.09、0.61 +/- 0.11、0.65 +/- 0.05、0.47 +/- 0.04、0.52 +/- 0.09 和 0.45 +/- 0.05，在 280、285、290、295、300、305、308、310 和 315nm 处，其中引用的误差（1sigma）表示实验分散度。在 308nm 处，乙二醇醛光解的平均 OH 量子产率为 0.11 +/- 0.02，其中引用的误差（1sigma）表示测量不确定性。从 308nm 处的乙二醇醛光解中检测到 CO、H(2)CO、(CHO)(2)、CH(3)OH、HCOOH 和 CO(2)等终产物。估计了 CO、H(2)CO、(CHO)(2)、CH(3)OH 和 HCOOH 的产率。我们还直接测量了 OH 自由基与乙二醇醛之间反应的速率常数。得到的速率常数为 (1.01 +/- 0.20) x 10(-11) cm(3) molecule(-1) s(-1)，其中引用的误差（1sigma）表示测量不确定性。讨论了结果的大气影响。
