Insights into the Oxygen Evolution Reaction on Graphene-Based Single-Atom Catalysts from First-Principles-Informed Microkinetic Modeling

Abstract

Single-atom transition metals embedded in nitrogen-doped graphene have emerged as promising electrocatalysts due to their high activity and low material cost. These materials have been shown to catalyze a variety of electrochemical reactions, but their active sites under reaction conditions remain poorly understood. Using first-principles density functional theory calculations, we develop a pH-dependent microkinetic model to evaluate the relative performance of transition metal catalysts embedded in fourfold N-substituted double carbon vacancies in graphene for the oxygen evolution reaction. We find that reaction pathways involving intermediates co-adsorbed on the metal site are preferred on all transition metals. These pathways lead to enhancements in catalytic activity and broaden the activity peak when compared with purely thermodynamics-based predictions. These findings demonstrate the importance of investigating reaction pathways on graphene-based catalysts and other twodimensional (2D) materials that involve metal active centers decorated by spectator intermediate species.

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“…the exchange correlation functional), 83,92 they should include important contributions such as solvation and dynamical effects, 93–95 the reaction barriers should be evaluated beyond the thermodynamic approximations and the computational data should be complemented by a microkinetic analysis. 96…”

Electrochemical reactions catalyzed by carbon dots from computational investigations: functional groups, dopants, and defects

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Two-Dimensional Layered Heterojunctions for Photoelectrocatalysis

“…pH-dependent MkM was used to evaluate the relative performance of 12 different transition metal catalysts embedded in 4-fold N-substituted double carbon vacancies in graphene for OER . It is revealed that the used methodology to calculate the reaction pathways led to the results with enhanced catalytic activity when compared to purely thermodynamics-based predictions, which underestimated onset potentials.…”