Kinetics of UV-H₂O₂ advanced oxidation in the presence of alcohols: the role of carbon centered radicals.
UV photolysis of aqueous hydrogen peroxide samples was carried out in the presence of methanol, ethanol, or t-butanol. The concentrations of H(2)O(2), dissolved O(2), and the alcohols were monitored as a function of time, and a quantitative chemical kinetics model for the photolysis of the solutions is presented. The observed kinetics consisted of an initial rapid consumption of dissolved oxygen followed by a significant acceleration in the photodecomposition of hydrogen peroxide. The acceleration phase was identified to originate from the fast feedback reaction between hydrogen peroxide and the carbon centered radicals resulting from hydrogen atom abstraction from the primary alcohols. In tertiary butanol solutions the radical species formed are more stable and do not react directly with H(2)O(2). As a consequence no significant acceleration of H(2)O(2) photolysis was observed in the presence of t-butanol.
Popov
Evgeny
E
Department of Chemistry and Biochemistry, California State University at Northridge, 18111 Nordhoff Street, Northridge, California 91330, USA.
Mametkuliyev
Muhamed
M
Santoro
Domenico
D
Liberti
Lorenzo
L
Eloranta
Jussi
J
D000438:Alcohols / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007700:Kinetics; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D012996:Solutions; D014466:Ultraviolet Rays
D000438:Alcohols; D012996:Solutions; D002244:Carbon; D006861:Hydrogen Peroxide; D010100:Oxygen