大気中の化学的動態におけるヒドロペロキシル基:一酸化炭素との反応
まとめ
ヒドロペロキシル基 (HO) と一酸化炭素 (CO) の間の反応は非常に遅いもので,速度定数は10〜20cm3/分子/秒未満です. この発見は,HO(2) 反応が地球の大気中のCOをCO(2) に大幅に変換しないことを示唆しています.
科学分野:
- 大気化学 大気化学
- フォトケミストリー フォトケミストリー
- 化学動力学 化学動力学
背景:
- 炭素一酸化物 (CO) は,大気中の重要な汚染物質です.
- CO酸化経路の理解は,大気モデリングに不可欠です.
- ハイドロペロキシル基 (HO(2) は,大気中の酸化サイクルにおける重要な種である.
研究 の 目的:
- 反応の速度定数 HO(2) + CO --> CO(2) + OH を決定する.
- トロポスフィアとストラトスフィアにおけるCOのシンクとしてのこの反応の重要性を評価する.
主な方法:
- CO,H(2) O,Ar,およびO(2) ((18,18) 混合物の低強度光分解.
- CO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2とCO2と
- 300 Kの速度常数の決定.
主要な成果:
- HO(2) + COの速度常数は,300 Kで<=10(-20) cm(3) /分子/秒であると決定されました.
- この反応速度は,大気条件において以前に想定されたより大幅に遅い.
結論:
- 熱化したHO(2) とCOの反応は,トロポスフィアのCOからCO(2) への変換にはほとんど重要ではない.
- この反応経路は,平流圏における沈没メカニズムとしても無意味です.
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