Phenol Decomposition by Pulsed‐Discharge Plasma Above a Water Surface in Oxygen and Argon Atmosphere

By‐products from phenol by the exposure of pulsed‐discharge plasma above a phenol aqueous solution are investigated by gas chromatography mass spectrometry, and the decomposition process of phenol is deduced. When Ar is used as a background gas, catechol, hydroquinone, and 4‐hydroxy‐2‐cyclohexene‐1‐one are produced, and no O 3 is detected; therefore, active species such as OH, O, HO 2 , H 2 O 2 , which are produced from H 2 O in the discharge, can convert phenol into those by‐products. When O 2 is used as a background gas, formic acid, maleic acid, succinic acid, and 4,6‐dihydroxy‐2,4‐hexadienoic acid are produced in addition to catechol and hydroquinone. O 3 is produced in the discharge plasma, so that phenol is probably decomposed into 4,6‐dihydroxy‐2,4‐hexadienoic acid by 1,3‐dipolar addition reaction with O 3 , and then 4,6‐dihydroxy‐2,4‐hexadienoic acid can be decomposed into formic acid, maleic acid, and succinic acid by a 1,3‐dipolar addition reaction with O 3 . © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(1): 1–9, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22419