Formation of Hydrogen Peroxide from O^–(H₂O)_n Clusters

Abstract

Hydrogen peroxide (H2O2) has recently received much attention as a safe and clean energy carrier for hydrogen molecules. In this study, based on direct ab initio molecular dynamics (AIMD) calculations, we demonstrated that H2O2 is directly formed via the photoelectron detachment of O–(H2O) n (n = 1–6) (water clusters of an oxygen radical anion). Three electronic states of oxygen atoms were examined in the calculations: O­(X)­(H2O) n (X = 3P, 1D, and 1S states). After the photoelectron detachment of O–(H2O) n (n = 1) to the 1S state, a complex comprising O­(1S) and H2O, O­(1 S)-OH2, was formed. A hydrogen atom of H2O immediately transferred to O­(1S) during an intracluster reaction to form H2O2 as the final product. Simulations were run to obtain a total of 33 trajectories for n = 1 that all led to the formation of H2O2. The average reaction time of H2O2 formation was calculated to be 57.7 fs in the case of n = 1, indicating that the reaction was completed within 100 fs of electron detachment. All the reaction systems O­(1S)­(H2O) n (n = 1–6) indicated the formation of H2O2 by the same mechanism. The reaction times for n = 2–6 were calculated to range between 80 and 180 fs, indicating that the reaction for n = 1 is faster than that of the larger clusters, that is, the larger the cluster size, the slower the reaction is. The reaction dynamics of the triplet O­(3P) and singlet O­(1D) potential energy surfaces were calculated for comparison. All calculations yielded the dissociation product O­(X)­(H2O) n → O­(X) + (H2O) n (X = 3P and 1D), indicating that the O­(1S) state contributes to the formation of H2O2. The reaction mechanism was discussed based on the theoretical results.

Elucidation of Molecular‐level Mechanisms of Oxygen Atom Reactions with Chlorine Ion in NaCl Solutions using Molecular Dynamics Simulations Combined with Density Functional Theory

“…A significant difference was observed between the behavior of O atoms in singlet state O( 1 D) and the triplet state O( 3 P).We could not observe the chemical reactions of the triplet oxygen atom during the simulation of a runtime of 3000 fs, which provided evidence of the relative stability of O( 3 P) in the liquid phase. This was also reported in other simulation works [35,[39][40][41]. Whereas we observed chemical reactions with chloride ions for singlet oxygen radical.…”

“…This was also reported in other simulation works. [35,[39][40][41] Whereas we observed chemical reactions with chloride ions for singlet oxygen radical. The reaction products and mechanisms depended on the NaCl concentration.…”

Hydrogen Storages Based on Graphene Nano-Flakes: Density Functional Theory Approach

“…This specific property makes the GNF-Mg-H2 system suitable for use as a H2 storage device with adsorption-desorption reversible properties. In the following sections, the direct AIMD calculations [46][47][48] for the electron and hole capture processes of the GNF-Mg-H2 system are described [45].…”

Reaction mechanism of an intracluster SN2 reaction induced by electron capture

“…In this study, the S N 2 reaction mechanism in the NF 3 –CH 3 Cl cluster induced by electron capture was investigated using a direct ab initio molecular dynamics (AIMD) method. 37–39 The reaction is expressed asNF 3 –CH 3 Cl + e − → [(NF 3 –CH 3 Cl) − ] ver → NF 2 + CH 3 F + Cl − where [(NF 3 –CH 3 Cl) − ] ver is the structure of (NF 3 –CH 3 Cl) − at the vertical electron capture point of the neutral parent cluster. Fig.…”