Photocatalysed transformation of chloroaromatic derivatives on zinc oxide II: Dichlorobenzenes

✍ Scribed by Tahar Sehili; Pierre Boule; Jacques Lemaire

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 955 KB
• Volume: 50
• Category: Article
• ISSN: 1010-6030
• DOI: 10.1016/1010-6030(89)80024-3

✦ Synopsis

The oxidative transformation of dichlorobenzenes photocatalysed by ZnO in aqueous solution has been studied using high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). Many photoproducts were detected and their formation was quantitatively evaluated. With 1,3-dichlorobenzene an ortho or para hydroxylation is primarily observed and no dechlorination occurs. With 1,2and 1,4-dichlorobenzene hydroxylation can occur with or without dechlorination. It is concluded that the reaction is influenced by adsorption and desorption phenomena. Self-inhibition is observed, which is explained by the reaction of 'OH radicals with the adsorbed primary products and by the formation of non-desorbing dimers, whereas the formation of H,02 occurs with a constant rate. The total inhibition by ethanol is attributed to the scavenging of . OH radicals involved in the first step of the reaction.