1,3-二甲基-5-亚硝基-6-氨基脲嘧啶铂电极电化学加氢机理研究

采用稳态极化法、循环伏安法和恒电位库仑法对1,3-二甲基-5-亚硝基-6-氨基脲嘧啶在铂电极上的电化学加氢机理进行了研究,研究介质为硫酸和硫酸钾水溶液.结果表明,pH=3时,1,3-二甲基-5-亚硝基-6-氨基脲嘧啶在铂电极析氢电位(-600～-800mV,vs.饱和硫酸钾的硫酸亚汞参比电极)前,发生加氢还原反应,氢离子在铂电极表面得到电子生成原子态的氢参与反应.随着pH值降低,加氢反应速度增大,还原电位正移.在铂电极上的电化学加氢过程受扩散控制,增大搅拌速度和提高温度都可提高反应速度.

Electrochemical Hydrogenation Mechanism of 6-Amino-5-nitroso-1,3-dimethyluracil on Pt Electrode

The electrochemical hydrogenation mechanism of 6-amino-5-nitroso-1,3-dimethyluracil on Pt electrode was studied by steady state polarization, cyclic voltammetry and constant-potential coulometry. One irreversible peak was found in the range of -600_-800 mV(vs. Hg/Hg 2SO 4) by cyclic voltammetry in pH=3 aqueous solution. The number of electrons involved in the electrochemical reaction was 4. One electron and one hydrogen ion were involved in the rate-determined step of electron transfer process. The reaction was controlled by diffusion and the reaction rate increased with increasing temperature and stirring speed and with decreasing pH.