高等学校化学学报 ›› 2003, Vol. 24 ›› Issue (8): 1464.

• 论文 • 上一篇    下一篇

酸性溶液中NaH2PO2在铂电极上氧化的原位红外光谱研究

蒋太祥, 吴辉煌   

  1. 厦门大学化学化工学院, 固体表面物理化学国家重点实验室, 厦门 361005
  • 收稿日期:2002-09-02 出版日期:2003-08-24 发布日期:2003-08-24
  • 通讯作者: 吴辉煌(1942年出生),男,教授,博士生导师,从事应用电化学研究.E-mail:hhwu@xmu.edu.cn E-mail:hhwu@xmu.edu.cn
  • 基金资助:

    国家自然科学基金(批准号:20073035)资助

In-situ IR Spectroscopic Study of Oxidation of NaH2PO2on Pt Electrodes in Acidic Solutions

JIANG Tai-Xiang, WU Hui-Huang   

  1. College of Chemistry and Chemical Engineering, State Key Laboratory for Physical Chemistry of the Solid Surfaces, Xiamen University, Xiamen 361005, China
  • Received:2002-09-02 Online:2003-08-24 Published:2003-08-24

摘要: 用SNIFTIRS和循环伏安法研究酸性溶液中次亚磷酸钠在多晶铂电极上的电氧化机理.分析了0.5mol/LH2SO4+0.1mol/LNaH2PO2溶液中原位红外反射谱图与电极电位的关系,发现在发生反应的电位下Pt电极上的吸附物种有氢原子和H2PO2,最终的氧化产物是H3PO4而不是H2PO3-,据此提出了酸性介质中次亚磷酸根离子在Pt上氧化的新机理.

关键词: 次亚磷酸根离子, 电氧化, 化学镀, 铂电极

Abstract: The mechanism of electrochemical oxidation of hypophosphite on a polycrystalline platinum electrode was studied by SNIFTIRS (i.e. Subtractively Normalized Interfacial FTIR Spectroscopy) as well as by cyclic voltammetry.The in-situ IR reflectance spectra were analyzed as a function of the Pt electrode potentials in 0.5 mol/L H2SO4+0.1 mol/L NaH2PO2solution.The in-situ IRband characteristics are those near 2100, 1250 and 1110cm-1, assigned as the presence of adsorbed hydrogen atom on Pt and non-adsorbed H3PO4molecule or phosphate species, respectively.It was concluded that both hydrogen atoms and H2PO2are the adsorbed species on Pt in the potential range where the oxidation occurs, and the final oxidation product was H3PO4rather than phosphate, different from the oxidation of hypophosphite on Ni electrode.Accordingly, a new mechanism was proposed for the hypophosphite oxidation on Pt electrodes in acidic media, i.e. in the potential range lower than 0.8 V(vs.SCE) the adsorbed H2PO2was directly oxidized to phosphate via phosphite, and in the potential range higher than 0.8 V the oxygen-adsorbed species on Pt participates in the oxidation of H2PO2into phosphate.

Key words: Hypophosphite, Electrooxidation, Chemical plating, Platinum electrode, SNIFTIRS

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