双反应活性中心催化体系降解木质素模型物的研究

Study on the Degradation of Lignin Model Compound Using a Dual Reaction Active Center Catalytic System

以硝酸铜和硝酸铁为原料,制备以活性炭为载体的铜-铁双金属复合催化剂,将其用于活化过硫酸盐,以实现对木质素模型物阿魏酸的降解;探讨催化剂制备的最佳反应条件和反应条件对材料催化活化效率的影响。结果表明,当活性炭质量分数为6%、催化剂(Cu^(2+)∶Fe^(3+)=2∶1,物质的量比)用量为0.03 g/L、过硫酸钠浓度为0.05 mol/L、pH值=7时,反应60 min,能够降解90%的阿魏酸。通过分析降解中间产物发现,阿魏酸可通过一系列氧化反应降解为小分子羧酸。通过电子顺磁共振技术表征表明,该催化体系中的主要反应活性物种是硫酸根自由基和羟基自由基。同时,催化剂具有良好的稳定性和循环利用性。

A copper-iron bimetallic composite catalyst supported on activated carbon was prepared by using copper nitrate and iron nitrate as raw materials,which was utilized to activate persulfate to degrade lignin model compound(ferulic acid).The optimum reactim conditions and effects of catalyst preparation conditions and reaction conditions on the catalytic activation efficiency of the material were also explored.It was found that 90%of ferulic acid could be degraded under the optimum condition(AC content was 6%,sodium persulfate concentration was 0.05 mol/L,dosage of catalyst was 0.03 g/L with molar ratio of Cu^(2+)to Fe^(3+)of 2∶1,pH value was 7).Through the analysis of degrada‐tion intermediates,it was found that ferulic acid molecules could be degraded into carboxylic acids with small molecule weight through a se‐ries of oxidation reactions.Characterization by electron paramagnetic resonance technology indicated that the main reactive species in the catalytic system were sulfate radicals and hydroxyl radicals.The catalyst possessed good stability and recyclability.