Perspectives on the Competition between the Electrochemical Water and N2 Oxidation on a TiO2(110) Electrode

The electrochemical nitrogen oxidation reaction (NOR) has recently drawn attention due to promising experimental and theoretical results. It provides an alternative, environmentally friendly route to directly synthesize nitrate from N2(g). There is to date a limited number of investigations focused on the electrochemical NOR. Herein, we present a detailed computational study on the kinetics of both the NOR and the competing oxygen evolution reaction (OER) on the TiO2(110) electrode under ambient conditions. The use of grand canonical density functional theory in combination with the linearized Poisson-Boltzmann equation allows a continuous tuning of the explicitly applied electrical potential. We find that the OER may either promote or suppress the NOR on TiO2(110) depending on reaction conditions. The detailed atomistic insights provided on the mechanisms of these competing processes make possible further developments toward a direct electrochemical NOR process.

Automated summary

The electrochemical nitrogen oxidation reaction (NOR) is a promising alternative route for directly synthesizing nitrate from N2(g). However, the understanding of NOR and its competing processes, such as the oxygen evolution reaction (OER), on TiO2(110) electrodes under ambient conditions is limited. In this study, a computational investigation combining grand canonical density functional theory with the linearized Poisson-Boltzmann equation was conducted to explore the kinetics of NOR and OER. The results reveal that the occurrence of OER can either promote or suppress NOR, depending on the reaction conditions. This detailed atomistic understanding offers potential for further developments in direct electrochemical NOR processes.