In-situ IR spectroscopic study of oxidation of NaH2PO2 on pt electrodes in acidic solutions
- 化学化工－已发表论文 
The mechanism of. electrochemical oxidation of hypophosphite on apolycrystalline 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 NaH2PO2 solution. The in-situ IR band characteristics are those near 2 100, 1 250 and 1 110 cm(-1), assigned as,the presence of adsorbed hydrogen atom on Pt and non-adsorbed H2PO2 molecule or phosphate species, respectively., It was, concluded that both hydrogen atoms and H2PO2 are the adsorbed species on Pt in the potential range where the. oxidation occurs, and the final. oxidation product was H,PO, rather 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 H2PO2 was 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 H2PO2 into phosphate.