过氧化氢氧化邻苯二酚、对苯二酚反应动力学的研究

Kinetics of Catalytic Oxidation of Pyrocatechol or Hydroquinone by Hydrogen Peroxide

邻苯二酚、对苯二酚的过氧化反应是过氧化氢氧化苯酚联产苯二酚的副反应,为了减少羟化液中苯二酚的深度氧化,用乙酸和铁粉制备的Fe2+为催化剂,对邻苯二酚、对苯二酚单一物质的过氧化反应进行实验研究。实验结果表明,反应液中苯二酚浓度、过氧化氢浓度及催化剂浓度越高,邻苯二酚、对苯二酚的过氧化速率越快。由实验数据拟合得到邻苯二酚、对苯二酚过氧化反应宏观动力学的模型参数,其表观活化能分别为39.802,34.776kJ/mol,过氧化氢的反应级数分别为0.85,0.97。

Peroxidation of pyrocatechol and hydroquinone, which were side-reactions of phenol hydroxylation by hydrogen peroxide, were separately investigated, using Fe2+ as catalyst. The aim of the work was to reduce overoxidation of dihydroxybenzene in hydroxylation products. Initial reaction rates of pyrocatechol and hydroquinone were directly proportional to initial concentrations of dihydroxybenzene, hydrogen peroxide and catalyst. Macrokinetic parameters were obtained by regression of experimental data. Apparent activation energy of peroxidation of pyrocatechol and hydroquinone were 39.802 kJ/mol and 34.776 kJ/mol respectively, and reaction orders to hydrogen peroxide were 0.85 and 0.97 respectively.