对氨基酚在修饰碳糊电极上电氧化的PM6法研究（英文）  

Electrochemical catalytic oxidation of p-aminophenol at p-phenol modified graphite paste electrode bycyclic voltammetryand PM6 semi-empirical molecular orbital theory

作　　者：朱永春[1,2] 蒋清笑 苏桂田[2] 陈庆阳[2] 

机构地区：[1]沈阳师范大学能源与环境催化研究所,沈阳110034 [2]沈阳师范大学化学化工学院,沈阳110034

出　　处：《沈阳师范大学学报（自然科学版）》2016年第3期343-353,共11页Journal of Shenyang Normal University:Natural Science Edition

基　　金：supported by National Natural Science Foundation of China(20807563)

摘　　要：以重氮化反应将对氨基化学修饰在石墨粉表面上并构建成碳糊电极。在此修饰电极上对-氨基酚表现处电化学催化氧化行为,与裸电极相比,氧化峰电位负移了73mV,氧化峰电流升高了60%。为了从分子水平上深入了解这种催化氧化行为,以38个碳构成的石墨烯片段-对氨基-对氨基酚组成的分子簇模型,MOPAC2012软件包内的PM6半经验分子轨道法研究了真空条件下体系的电化学催化活性。计算结果表明,所有建立的分子簇模型都是热力学稳定的,都具有负的反应吉布斯自由能。前线分子轨道的分析给出了电化学催化诱导下的电子转移过程,并定性地解释了对氨基酚在修饰和未修饰电极上的电化学氧化机理。对氨基酚在修饰电极上的可交换电子量比在未修饰电极上的大了64.8%。此结果恰好与试验结果中的氧化峰电流的升高结果一致;试验结果中的氧化还原峰电位对计算结果中的相应最高占有轨道和最低空轨道能呈现很好的线性关系。The graphite powder surface is chemically modified by p-aminophenol with a diazoreaction, and used to compose a carbon paste electrode. At the modified electrode, p-aminophenol shows an electrochemical catalytic oxidation with an oxidation potential negatively shifted for about 73 mV and an increase of the oxidation peak current for about 60% compared with that at a carbon paste electrode without the modificatioru In order to deeply understand the catalytic oxidation from molecular view, PM6 of a semi-empirical quantum chemical method in MOPAC2012 software was used in the study of electrochemical catalytic activity of the system based on the molecular cluster models of a piece of graphene with 38 carbon atoms as the surface of graphite powder, paminophenol and its diazo-reaction product in vacuum conditions. The calculation results show that all the molecular cluster models are thermodynamic stable with negative Gibbs free energies of the reactions. The analysis of frontier orbital gives out an electron transfer induced electrochemical catalysis. The electrochemical redox mechanism of p-aminophenol at modified and unmodified carbon paste electrodes were qualitatively explained. The exchangeable electron of p-aminophenol at p-aminophenol modified carbon paste electrode is about 64. 8% larger than that at unmodified carbon paste electrode, which is accord well with the increase of oxidation peak current, and the anodic and cathodic potentials have a linear relation with the energies of HOMO and the LUMO of the molecular clusters of p-aminophenol.

关 键 词：半经验分子轨道理论 对氨基酚 化学修饰碳糊电极 电化学催化 石墨粉 

分 类 号：O646[理学—物理化学]