title: Enhancement of gaseous iodine emission by aqueous ferrous ions during the heterogeneous reaction of gaseous ozone with aqueous iodide.
abstract: Gaseous I2 formation from the heterogeneous reaction of gaseous ozone with aqueous iodide in the presence of aqueous ferrous ion (Fe(2+)) was investigated by electron impact ionization mass spectrometry. Emission of gaseous I2 increased as a function of the aqueous FeCl2 concentration, and the maximum I2 formation with Fe(2+) was about 10 times more than without Fe(2+). This enhancement can be explained by the OH(-) scavenging by Fe(3+) formed from Fe(2+) ozonation to produce colloidal Fe(OH)3. This mechanism was confirmed by measurements of aqueous phase products using a UV-vis spectrometer and an electrospray ionization mass spectrometer. We infer that such a pH-buffering effect may play the key role in general halogen activations.
authors.affiliation: Department of Chemical Systems Engineering, Graduate School of Engineering, The University of Tokyo, Tokyo 113-0033, Japan. y_sakamoto@ees.hokudai.ac.jp
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: Shinichi
authors.initials: S
authors.lastname: Enami
authors.forename: Kenichi
authors.initials: K
authors.lastname: Tonokura