The reaction of hydroxyl and methylperoxy radicals is not a major source of atmospheric methanol.
The reaction of hydroxyl and methylperoxy radicals is not a major source of atmospheric methanol.
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DOI：
10.1038/s41467-018-06716-x
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发表时间：
2018-10-19
影响因子：
16.6
通讯作者：
Taatjes CA
中科院分区：
文献类型：
--
作者：
Caravan RL;Khan MAH;Zádor J;Sheps L;Antonov IO;Rotavera B;Ramasesha K;Au K;Chen MW;Rösch D;Osborn DL;Fittschen C;Schoemaecker C;Duncianu M;Grira A;Dusanter S;Tomas A;Percival CJ;Shallcross DE;Taatjes CA
甲醇是理解对流层氧化的基准，但在大气模型中预测不足高达100%。最近的工作表明，这种差异可以通过羟基和甲基过氧基与甲醇支化分数为30%的快速反应来协调。然而，对于低于15%的馏分，甲醇预测不足的情况会加剧。该反应的理论研究具有挑战性，因为单重态和三重态表面之间存在系间交叉--∼45%的反应产物是通过前产物复合体的系间交叉获得的--这需要对产物分支进行实验测定。在这里，我们报道了从这个反应中直接测量甲醇的方法。建立了低于15%的分支分数，从而突显了对全球甲醇来源的理解存在很大差距。这些结果支持了近期高水平的理论工作，并大大减少了其不确定性。最近，羟基和甲基过氧基的反应被认为是在遥远的对流层中丢失甲醇的来源。在这里，作者提供了直接的实验测量，证明了该反应导致了对模拟甲醇的进一步低估。
Methanol is a benchmark for understanding tropospheric oxidation, but is underpredicted by up to 100% in atmospheric models. Recent work has suggested this discrepancy can be reconciled by the rapid reaction of hydroxyl and methylperoxy radicals with a methanol branching fraction of 30%. However, for fractions below 15%, methanol underprediction is exacerbated. Theoretical investigations of this reaction are challenging because of intersystem crossing between singlet and triplet surfaces – ∼45% of reaction products are obtained via intersystem crossing of a pre-product complex – which demands experimental determinations of product branching. Here we report direct measurements of methanol from this reaction. A branching fraction below 15% is established, consequently highlighting a large gap in the understanding of global methanol sources. These results support the recent high-level theoretical work and substantially reduce its uncertainties. The reaction of hydroxyl and methylperoxy radicals has recently been suggested as the source of missing methanol in the remote troposphere. Here, the authors present direct experimental measurements demonstrating the reaction leads to further underprediction of modelled methanol.
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影响因子：
6.3
作者：
Millet, D. B.;Baasandorj, M.;Xu, J.
通讯作者：
Xu, J.
影响因子：
3
作者：
Archibald, A. T.;Petit, A. S.;Shallcross, D. E.
通讯作者：
Shallcross, D. E.
影响因子：
4.4
作者：
Burkert, J;Andrés-Hernández, MD;Kraus, A
通讯作者：
Kraus, A
影响因子：
--
作者：
Detournay, Anais;Sauvage, Stephane;Galloo, Jean-Claude
通讯作者：
Galloo, Jean-Claude
影响因子：
2.8
作者：
Farago, Eszter P.;Schoemaecker, Coralie;Fittschen, Christa
通讯作者：
Fittschen, Christa