Reaction of CO2 with UO3 Nanoclusters

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2017-11, Vol.121 (44), p.8518-8524
• Main Authors: Flores, Luis A, Murphy, Julia G, Copeland, William B, Dixon, David A
• Format: Article
• Language: English
• Subjects: INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/acs.jpca.7b09107

Adsorption of CO2 to uranium oxide, (UO3) n , clusters was modeled using density functional theory (DFT) and coupled cluster theory (CCSD­(T)). Geometries and reaction energies were predicted for carbonate formation (chemisorption) and Lewis acid–base addition of CO2 (physisorption) to these (UO3) n clusters. Chemisorption of multiple CO2 moieties was also modeled for dimer and trimer clusters. Physisorption and chemisorption were both predicted to be thermodynamically allowed for (UO3) n clusters, with chemisorption being more thermodynamically favorable than physisorption. The most energetically favored (UO3)3(CO2) m clusters contain tridentate carbonates, which is consistent with solid-state and solution structures for uranyl carbonates. The calculations show that CO2 exposure is likely to convert (UO3) n to uranyl carbonates.