Comparative first principles‐based molecular dynamics study of catalytic mechanism and reaction energetics of water oxidation reaction on 2D‐surface

Abstract

The study of the water-splitting process, which can proceed in 2e − as well as 4e − pathway, reveals that the process is entirely an uphill process, and the third step, that is, the oxo oxo bond formation is the rate-determining step. The kinetic barrier of the oxygen evolution reaction (OER) on the 2D material catalysts in the presence of explicit solvents is scarcely studied. Here, we investigate the dynamics of the OER on the undoped graphene and the activation energy barrier of each step using first principles molecular dynamics simulations. Here we provide a detailed analysis of the kinetics of all the 4e − transfer steps of OER on the graphene surface. We also compare the accuracy of one of the density functional theory (DFT) functionals and density functional based tight binding (DFTB) method in explaining the OER steps. The comparative study reveals that DFTB can be used for performing metadynamics simulations quipped with much less computational cost than DFT functionals. By both Perdew-Burke-Ernzerhof and DFTB methods, the third step is revealed to be the rate-determining step with an energy barrier of 21.19 ± 0.51 and 20.23 ± 0.20 kcal mol −1 , respectively. DFTB gives an impression of being successful in predicting the energy barriers of OER in 4e-transfer pathway and comparable to the DFT method, and we would like to extend the use of DFTB for further studies with a sizable and complex system.

Treating Semiempirical Hamiltonians as Flexible Machine Learning Models Yields Accurate and Interpretable Results

“…The work here is restricted to SCF solutions for distorted structures of organic molecules consisting of C, N, O, and H. Future work includes extensions to additional elements such as transition metals, additional properties such as excitation energies , and reaction barriers, , and inclusion of additional interactions such as dispersion , and solvent interactions. , …”

Reconstructing reactivity in dynamic host–guest systems at atomistic resolution: amide hydrolysis under confinement in the cavity of a coordination cage

“…Considered the computational cost of these simulations, and the complexity of our systems, we employed a semi-empirical density-functional tight-binding (DF-TB) method, 45,46 in its selfconsistent charge corrected variant SCC-DFTB. 47 Recently shown to provide comparable accuracy to DFT with large basis sets in terms of prediction of barrier heights and reaction energies for organic molecules, [48][49][50] SCC-DFTB has indeed been already successfully used to investigate hydrolysis reactions in biological sys-tems. 51,52 Despite its approximations, this method guarantees satisfactory accuracy in our case at an affordable computational cost, 24 a point particularly relevant given that our method of choice, i.e.…”

Assessing Low-Cost Computational Methods against Structural Properties and Size Effects of Pt nanoparticles

“…The ReaxFF , reactive force field was tested in the same fashion. DFTB and the ReaxFF are well-known methods that have already been frequently employed in heterogeneous catalysis. − On the other hand, the recently developed GFN methods were first benchmarked against high-level DFT, wave function theory (WFT), and experimental data mainly for organic and metal–organic compounds. ,− However, their promising applications reported in the past few years − together with their low computational cost and their atom-specific parametrization make their accuracy worth to be assessed on metal NPs as well.…”