화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.158, No.12, C439-C444, 2011
The Role of Dissolved Hydrogen on Rare Earth-Doped Uranium Dioxide Corrosion in the Presence of Hydrogen Peroxide
Electrochemical and X-ray photoelectron spectroscopic (XPS) methods have been used to study the combined influence of H(2)O(2) and H(2) on the oxidation of SIMFUEL (UO(2)) electrodes in 0.1 mol.dm(-3) KCl (pH = 9.5) at 60 degrees C. The SIMFUEL electrodes contain RE(III) (rare earth) ions at U(IV) lattice sites within the UO(2) matrix. In both Ar-purged and H(2)/Ar-purged solutions the final corrosion potential values were dependent on [H(2)O(2)]; however, the XPS analyses showed no differences in the degree of oxidation of uranium, indicating no enduring effect of H(2) on the oxidation of UO(2) in H(2)O(2)- containing solutions. However, in H2/Ar-purged solutions the corrosion potential achieves considerably more positive transient values than in Ar-purged solutions before relaxing to the final value. A possible reason is that the U(IV) reversible arrow U(VI) redox cycle induced by hydrogen peroxide oxidation and hydrogen reduction activates the UO(2) surface, leading to a temporary enhancement of UO(2) dissolution (as UO(2)(2+)). (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.073112jes] All rights reserved.