Reaction of Ozone with Hydrogen Peroxide (Peroxone Process): A Revision of Current Mechanistic Concepts Based on Thermokinetic and Quantum-Chemical Considerations
Reaction of Ozone with Hydrogen Peroxide (Peroxone Process): A Revision of Current Mechanistic Concepts Based on Thermokinetic and Quantum-Chemical Considerations
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DOI：
10.1021/es100277d
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发表时间：
2010-05-01
影响因子：
11.4
通讯作者：
von Sonntag, Clemens
中科院分区：
文献类型：
--
作者：
Merenyi, Gabor;Lind, Johan;von Sonntag, Clemens
臭氧与H2 O2阴离子的反应（过氧化物过程）产生（OH）-O-中心点自由基（Staehelin，J.; Hoigne，J. Environ. Sci. 1982，16，676-681）。热动力学的考虑现在表明，最初假定为第一步的电子转移必须被加合物的形成所取代，HO 2- + O-3 -> HO 5-（Δ G度= -39.8 kJ mol（-1））。这分解成HO 2中心点和O-3（中心点-）（Δ G度= 13.2 kJ mol（-1））。HO 2中心点与O-2（中心点-）+ H+处于平衡，O-2（中心点-）经历电子转移到O-3，产生进一步的O-3（中心点-）。本文根据O-3（中心点-）可逆箭头O-2 + O中心点-和O中心点- + H_2O可逆箭头（OH）-O中心点+ OH-的平衡，讨论O-3衰变为（OH）-O中心点的过程，排除了原先假定的中间体HO_3中心点。为了解释观察到的过氧化物酮过程仅为50%的效率，提出了HO 5-衰变为2 O-2 + OH-（Δ G度= -197 kJ mol（-1））与衰变为HO 2中心点;和O-3（中心点-）的竞争。
The reaction of ozone with the anion of H2O2 (peroxone process) gives rise to (OH)-O-center dot radicals (Staehelin, J.; Hoigne, J. Environ. Sci. Technol. 1982, 16, 676-681). Thermokinetic considerations now suggest that the electron transfer originally assumed as the first step has to be replaced by the formation of an adduct, HO2- + O-3 -> HO5- (Delta G degrees = -39.8 kJ mol(-1)). This decomposes into HO2 center dot and O-3(center dot-) (Delta G degrees = 13.2 kJ mol(-1)). HO2 center dot is in equilibrium with O-2(center dot-) + H+ and O-2(center dot-) undergoes electron transfer to O-3 giving rise to further O-3(center dot-). The decay of O-3 into (OH)-O-center dot is now discussed on the basis of the equilibria O-3(center dot-) reversible arrow O-2 + O center dot- and O center dot- + H2O reversible arrow (OH)-O-center dot + OH-, excluding HO3 center dot as the intermediate originally assumed. To account for the observation of the peroxone process being only 50% efficient, the decay of HO5- into 2 O-2 + OH- (Delta G degrees = -197 kJ mol(-1)) is proposed to compete with the decay into HO2 center dot; and O-3(center dot-).