Kinetics of photocatalytic degradation of phenols with multiple substituent groups
Kinetics of photocatalytic degradation of phenols with multiple substituent groups
复制标题
DOI：
10.1016/j.jphotochem.2005.08.022
复制
发表时间：
2006-04-15
影响因子：
4.3
通讯作者：
Madras, G
中科院分区：
文献类型：
--
作者：
Priya, MH;Madras, G
用燃烧合成的催化剂研究了氯代、甲基和硝基取代的7种苯酚的光催化降解。对中间产物进行了分析，提出了可能的降解途径。测定了不同酚类化合物降解的一级动力学速率常数。光催化降解速率顺序为：4-氯，3-甲基苯酚；2-氯，4-甲基苯酚；4-氯，2-硝基苯酚；4-氯，2-甲基苯酚；4-氯，3-硝基苯酚与2-氯，4-硝基苯酚；4-甲基，2-硝基苯酚。4-氯，3-甲基苯酚的总降解速率比4-甲基，2-硝基苯酚的降解速率快近一个数量级。氯甲基苯酚的降解速度快于氯硝基苯酚，这是由于硝基对羟基自由基的攻击具有环失活特性。在决定多取代苯酚的降解率时，取代基的性质比取代基的位置起着更重要的作用。(C)2005 Elsevier B.V.保留所有权利。
The photocatalytic degradation of seven phenols, substituted with two of the following groups: chloro, methyl and nitro, was investigated using combustion-synthesized catalyst. The intermediates were analyzed and a possible pathway of degradation was proposed. The first order kinetic rate constants for the degradation of various phenols were determined. The rate of photocatalytic degradation followed the order: 4-chloro,3-methyl phenol > 2-chloro,4-methylphenol > 4-chloro,2-nitrophenol > 4-chloro,2-methyl phenol > 4-chloro,3-nitrophenol similar to 2-chloro,4-nitrophenol > 4-methyl,2-nitrophenol. The overall degradation rate of 4-chloro,3-methyl phenol was nearly an order of magnitude faster than the degradation rate of 4-methyl,2-nitrophenol. Chloromethylphenols degraded faster than chloronitrophenols due to the ring deactivating characteristic of nitro group for hydroxyl radical attack. The nature of substituent groups plays a more important role than the position of the substituent groups in determining the degradation rate of multi-substituted phenols. (c) 2005 Elsevier B.V. All rights reserved.