Reaction of Ozone with Hydrogen Peroxide (Peroxone Process): A Revision of Current Mechanistic Concepts Based on Thermokinetic and Quantum-Chemical Considerations
2010 (English)In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 44, no 9, 3505-3507 p.Article in journal (Refereed) Published
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-).
Place, publisher, year, edition, pages
2010. Vol. 44, no 9, 3505-3507 p.
ADVANCED OXIDATION PROCESSES, HYDROXYL RADICALS, PULSE-RADIOLYSIS, KINETICS, WATER, DECOMPOSITION, OZONATION, BROMIDE, DENSITY, IONS
IdentifiersURN: urn:nbn:se:kth:diva-28231DOI: 10.1021/es100277dISI: 000277067000051ScopusID: 2-s2.0-77951823658OAI: oai:DiVA.org:kth-28231DiVA: diva2:389456
QC 201101192011-01-192011-01-122011-01-19Bibliographically approved