Comparative density functional theory study for predicting oxygen reduction activity of single-atom catalyst

TL;DR

This study compares various density functional theory functionals to accurately predict oxygen reduction activity of TM-N4 catalysts, highlighting the importance of functional choice for reliable catalytic activity predictions.

Contribution

It systematically evaluates different exchange-correlation functionals for predicting ORR activity on TM-N4 catalysts, providing guidance on functional selection for accurate modeling.

Findings

RPBE+D3 and BEEF-vdW yield similar overpotentials.

Choice of functional significantly impacts predicted catalytic activity.

Proper functional selection is crucial for reliable DFT predictions.

Abstract

It has been well established that nitrogen coordinated transition metal, TM-N$_{4}$-C (TM$=$Fe and Co) moieties, are responsible for the higher catalytic activity for the electrochemical oxygen reduction reaction. However, the results obtained using density functional theory calculations vary from one to another, which can lead to controversy. Herein, we assess the accuracy of the theoretical approach using different class of exchange-correlation functionals, i.e., Perdew-Burke-Ernzerhof (PBE) and revised PBE (RPBE), those with the Grimme's semiempirical dispersion correction (PBE+D3 and RPBE+D3), and the Bayesian error estimate functional with the nonlocal correlation (BEEF-vdW) on the reaction energies of oxygen reduction reaction on TM-N$_{4}$ moieties in graphene and those with OH-termination. We found that the predicted overpotentials using RPBE+D3 are comparable and consistent with those using BEEF-vdW. Our finding indicates that a proper choice of the exchange-correlation functional is crucial to a precise description of the catalytic activity of this system.