Oxidation Mechanism of Hypophosphite

Authors

Dong-bai SUN, UNDP-Beijing Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083
Ying JIN, UNDP-Beijing Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083
Hong-ying YU, UNDP-Beijing Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083
De-jun YANG, UNDP-Beijing Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083

Corresponding Author

Dong-bai SUN

Abstract

There exist two oxidation current peaks on the anodic polarization curve between -0.7 V and 0 V (SCE) in Na-hypophosphite solution. Peak Ⅰ (-0.55 V, SCE) , which represents the oxidation process from H₂PO₂^- to H₂PO₃^-, has been studied previously. Peak Ⅱ, which is located at the potential about -0.4 V (SCE), is investigated emphatically in this paper. The results show that, peak Ⅰ and Ⅱ are corresponding to two successive steps in oxidation process of H₂PO₂^-, i.e. peak Ⅱ corresponds to the oxidation process of adsorped (HPO₂)_ads, an intermediate product of electrode reaction of peak Ⅰ, to PO₃^4-. The rate limiting step in the electrode process from (HPO₂) ads to H₂PO₃^- is the desorption of (HPO₂)_ads, and the desorption rate constant is estimated as 2.32±0.20 s^-1. A new schematic of oxidation process of hypophosphite is proposed.

Keywords

Hypophosphite, Oxidation, Cyclic voltammetry References

DOI Link

https://doi.org/10.61558/2993-074X.3154

Publication Date

1999-02-28

Online Available Date

1999-02-28

Revised Date

1998-05-26

Received Date

1998-02-26

Recommended Citation

Dong-bai SUN, Ying JIN, Hong-ying YU, De-jun YANG. Oxidation Mechanism of Hypophosphite[J]. Journal of Electrochemistry, 1999 , 5(1): 36-42.
DOI: 10.61558/2993-074X.3154
Available at: https://jelectrochem.xmu.edu.cn/journal/vol5/iss1/8