Water OH Bond Activation by Gas‐Phase Plutonium Atoms: Reaction Mechanisms and Ab Initio Molecular Dynamics Study

Abstract

A thorough description of the reaction mechanisms, taking into account different possible spin states, offers insights into the gas-phase reaction of plutonium atoms with water. Two possible reactions (isomerization and dehydrogenation) are presented. These reactions are found to be exothermic, with the best thermochemical conditions observed for the dehydrogenation reaction at around 23.5 kcal mol(-1). The nature of the chemical-bonding evolution along the reaction pathways are investigated by employing various methods including electron localization function, atoms in molecules, and Mayer bond order. Total, partial, and overlap population density of state diagrams and analyses are also presented. Reaction rates at elevated temperatures (T=298-2 000 K) are calculated by using variational transition-state theory with one-dimensional tunneling effects. In dynamics simulations, only the dehydrogenation reaction is observed, and found to be in good agreement with experimental values.

Reaction mechanism of hydrogen cyanide catalyzed by gas‐phase titanium

“…A positive H(r) implies the closed‐shell interaction, whereas negative H(r) is regarded as the standard of covalent character . The H(r) standard was proven to be very appropriate to characterize the nature of a bond for heavy‐atom systems …”

“…[9,29] The H(r)standard was proven to be very appropriate to characterize the nature of a bond for heavy-atom systems. [30][31][32] For the sake of simplicity, only a few main stationary points are analyzed as example.…”

Ab initio molecular dynamics study of the interaction of plutonium with oxygen in the gas phase

“…Using theory, several investigations into the reaction mechanisms of actinide atoms with small molecules have been performed using different calculation methods. In fact, detailed reaction processes have been obtained for the following systems: Pu + H 2 O, 29 PuO 2 + H 2 , 30,31 Th + NH 3 , 32 and Th + (Th 2+ ) + H 2 O. 33 These studies demonstrated the reaction mechanisms and electronic structures along the minimum energy reaction pathways as well as the potential energy proles.…”

Can water continuously oxidize the PuO molecule? Mechanisms, topological analysis and rate constant calculations

“…2,3 Therefore, over the last few decades, the reaction of plutonium with small molecules in the gas phase has attracted signicant attention both in experimental [1][2][3][4][5][6][7][8][9][10][11][12] and theoretical studies. [13][14][15][16][17][18][19][20][21] In addition, the reaction of plutonium with water which can provide some insight into the corrosive mechanism of steam on nuclear fuel is a more imperative and challenging research eld.…”

“…In our recent theoretical study, 21 the mechanisms and molecular dynamics of the reaction of gas phase Pu atom with H 2 O were investigated by DFT computation. The reaction pathways shown in the following equations were determined.…”