摘要
应用 Stopped- flow光谱仪研究苯酚在 2 88～ 30 8K和 p H=3.2～ 9.8的 O3 / H2 O2 氧化反应动力学。通过实验及分析认为 :在不同酸度的实验条件下苯酚 O3 / H2 O2 氧化降解的途径及动力学不同。在酸性及弱酸性(p H=6 .5 )下苯酚 O3 / H2 O2 氧化反应机理是苯酚直接为 O3 氧化 ,在碱性 (p H=9.8)
The reaction kinetics of phenol chemical oxidation by the O 3/H 2O 2 process was investigated in the pH values ranging from 3.2～9.8 at temperatures varying from 288 to 308 K utilizing the stopped flow spectrophometer. The conclusion coming from experiments and analyses is that the pathways and the reaction kinetics of phenol peroxone oxidation are different in various acidity. The reaction mechanism is direct oxidation of phenol with ozone molecules in acidic (pH=3.2) and weak acidic (pH=6.5) conditions, the overall kinetics of the peroxone ozonation of phenol is 0.35 order with respect to the concentration of phenol and independent of the concentrations of the ozone and H 2O 2 at pH3.2, and the overall kinetics of the peroxone ozonation of phenol is 1.3 order with 0.3 order in the concentration of phenol and first order in the concentrations of the ozone and independent of the concentrations of H 2O 2 at pH6.5. The hydroxyl radical mechanism is dominating in alkaline solutions (pH=9.8), and the overall kinetics of the peroxone ozonation of phenol is 1.35 order with first order in the concentration of in the concentration of ozone and 0.35 order in the concentration of H 2O 2 and independent of the concentrations of phenol. The rate constant increases with temperature, and the activation energy of 17.2kJ/mol at pH3.2 was obtained
出处
《化学反应工程与工艺》
EI
CAS
CSCD
北大核心
2001年第1期55-60,共6页
Chemical Reaction Engineering and Technology
基金
广东省自然科学基金资助项目! (990 6 42 )
