利用静态容量法测定了288 K下CO、CO2和O2在UO2表面的吸附等温线,利用压降法结合原位显微观测研究了CO、CO2和O2对铀氢初始反应的影响.结果表明,3种气体在U02表面的吸附强弱关系为O2＞CO2 ＞CO,Langmuir和Freundlich方程分别较好描述了CO、CO2的等温吸附行为.含氧气体对孕育期的影响与其吸附特性密切相关,3种气体阻抑效应的强弱关系为CO2＞CO＞O2.CO和O2对孕育期的影响近呈线性关系,CO2对孕育期的影响则与CO2含量有关.CO和CO2的阻抑机制主要是气体分子对铀表面活性位的优先占据,而O2的阻抑机制相对复杂,可能涉及水分子前驱态的形成和吸附O粒子扩散两种表面化学过程.根据阻抑机制和吸附特性导出的数学模型较好描述了CO和CO2对孕育期的影响规律.
参考文献
| [1] | Ben-Eliyahu Y;Brill M .[J].Journal of Chemical Physics,1999,111:6053. |
| [2] | Cohen D;Zeiri Y;Mintz M H .[J].Journal of Alloys and Compounds,1992,184:11. |
| [3] | Glascott J .[J].Sci Technol J AWE,2003,6:16. |
| [4] | Teter D F;Hanrahan R J;Wetteland C J .Uranium Hydride Nucleation Kinetics:Effects of Oxide Thickness and Vacuum Outgassing,LA-13772-MS[R].Los Alamos:Los Alamos National Laboratory,2001. |
| [5] | Harker R M .[J].Journal of Alloys and Compounds,2006,426:106. |
| [6] | Bloch J;Brami D;Kremner A et al.[J].Journal of the Less-Common Metals,1988,139:371. |
| [7] | Moreno D;Arkush R;Zalkind S et al.[J].Journal of Nuclear Materials,1996,230:181. |
| [8] | Arkush R;Venkert A;Aizenshtein M et al.[J].Journal of Alloys and Compounds,1996,244:197. |
| [9] | Scott, TB;Allen, GC;Findlay, I;Glascott, J .UD3 formation on uranium: evidence for grain boundary precipitation[J].Philosophical magazine,2007(2):177-187. |
| [10] | Hanrahan R J;Hawley M E;Brown G W .The lnfluence of Surface Morphology and Oxide Microstructure on the Nucleation and Growth of Uranium Hydride on Alpha Uranium,LA-UR-98-2193[R].Los Alamos:Los Almos National Laboratory,1998. |
| [11] | Colmenares C A .[J].Journal of Physical Chemistry,1974,78:2117. |
| [12] | Haschke J M;Allen T H;Morales L A .[J].Journal of Alloys and Compounds,2001,314:78. |
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