TY - JOUR
T1 - Energetics of hydration on uranium oxide and peroxide surfaces
AU - Guo, Xiaofeng
AU - Wu, Di
AU - Ushakov, Sergey V.
AU - Shvareva, Tatiana
AU - Xu, Hongwu
AU - Navrotsky, Alexandra
N1 - Funding Information:
This work was supported by the Materials Science of Actinides (MSA), an Energy Frontier Research Center (EFRC), funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DESC0001089, and the Laboratory Directed Research and Development (LDRD) program (Project #20180007 DR) of Los Alamos National Laboratory (LANL). We thank Peter Burns for his support of this work through leading the MSA EFRC, and X.G. acknowledges support through a LANL Seaborg postdoctoral fellowship and, later, institutional funds from the Department of Chemistry at Washington State University. D.W. was also supported by the institutional funds from the Gene and Linda Voiland School of Chemical Engineering and Bioengineering at Washington State University. D.W. and X.G. acknowledge the fund of Alexandra Navrotsky Institute for Experimental Thermodynamics. LANL, an affirmative action/ equal opportunity employer, is managed by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy under contract 89233218CNA000001.
Publisher Copyright:
Copyright © 2019 Materials Research Society.
PY - 2019/10/14
Y1 - 2019/10/14
N2 - Enthalpies of water adsorption on amorphous and crystalline oxides and peroxides of uranium are reported. Despite substantial structural and computational research on reactions between actinides and water, understanding their surface interactions from the energetic perspective remains incomplete. Direct calorimetric measurements of hydration energetics of nano-sized, bulk-sized UO2, U3O8, anhydrous γ-UO3, amorphous UO3, and U2O7 were carried out, and their integral adsorption enthalpies were determined to be -67.0, -70.2, -73.0, -84.1, -61.6, and -83.6 kJ/mol water, with corresponding water coverages of 4.6, 4.5, 4.1, 5.2, 4.4, and 4.1 H2O per nm2, respectively. These energetic constraints are important for understanding the interfacial phenomena between water and U-containing phases. Additionally, this set of data also helps predict the absorption and desorption behavior of water from nuclear waste forms or used nuclear fuels under repository conditions. There are also underlying relations for water coverage among different U compounds. These experimentally determined data can be used as benchmark values for future computational investigations.
AB - Enthalpies of water adsorption on amorphous and crystalline oxides and peroxides of uranium are reported. Despite substantial structural and computational research on reactions between actinides and water, understanding their surface interactions from the energetic perspective remains incomplete. Direct calorimetric measurements of hydration energetics of nano-sized, bulk-sized UO2, U3O8, anhydrous γ-UO3, amorphous UO3, and U2O7 were carried out, and their integral adsorption enthalpies were determined to be -67.0, -70.2, -73.0, -84.1, -61.6, and -83.6 kJ/mol water, with corresponding water coverages of 4.6, 4.5, 4.1, 5.2, 4.4, and 4.1 H2O per nm2, respectively. These energetic constraints are important for understanding the interfacial phenomena between water and U-containing phases. Additionally, this set of data also helps predict the absorption and desorption behavior of water from nuclear waste forms or used nuclear fuels under repository conditions. There are also underlying relations for water coverage among different U compounds. These experimentally determined data can be used as benchmark values for future computational investigations.
KW - calorimetry
KW - surface enthalpy
KW - uranium oxide
KW - uranium peroxide
KW - water adsorption
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U2 - 10.1557/jmr.2019.192
DO - 10.1557/jmr.2019.192
M3 - Article
AN - SCOPUS:85067346763
SN - 0884-2914
VL - 34
SP - 3319
EP - 3325
JO - Journal of Materials Research
JF - Journal of Materials Research
IS - 19
ER -