Theoretical Evaluation of Highly Efficient Nitrate Reduction to Ammonia on InBi

Abstract

Electrocatalytic reduction of nitrate to ammonia has become a popular approach for wastewater treatment and ammonia production. However, the development of highly efficient electrocatalysts remains a great challenge. Herein, we systematically studied the potential of InBi for nitrate reduction to ammonia (NRA) based on density functional theory (DFT) calculations. Our results reveal that InBi exhibits high activity for NRA via an O-end pathway, where the free energy evolution of all intermediates is downhill in the most favorable elementary steps. The activation of nitrate originates from the strong orbital hybridization between oxygen and indium atoms, leading to an enhanced charge transfer as well as NO 3 − adsorption. In particular, the competing hydrogen evolution reaction (HER) is effectively suppressed due to the weak adsorption of proton. Our study not only proves the great electrocatalytic potential of InBi as a novel catalyst for NRA but also points out a new way to design NRA electrocatalysts for practical applications.

Green synthesis of a magnesium single-atom catalyst from Spinacia oleracea chlorophyll extracts for sustainable electrocatalytic nitrate reduction to ammonia

“…The following proton-electron transfers to *NO leading to *NHO (NRA1, ΔG = −0.67 eV) and *NOH (NRA2, ΔG = +0.56 eV) are reported to be the potential determining steps (PDS) in many previous reports. 41,42 The reaction is likely to proceed through NRA1 to *NHO as it is thermodynamically more favorable. Furthermore, proton-electron transfer to the oxygen atom of *NHO leads to *NHOH, which upon subsequent protonation and dehydration leads to *NH.…”

Electrochemical Nitrate Reduction: Ammonia Synthesis and the Beyond

“…Nevertheless, some intermediates are hard to be observed due to extremely short presence, in which occasion theoretical simulation from DFT is helpful to clarify the reaction pathway and screen the most efficient catalyst. [52,[74][75][76] The state-of-art characterization methods for investigating the mechanism of nitrate electroreduction will be covered when introducing materials to give a direct understanding, and interested readers may find more details in previous works. [77,78] 3.…”

DFT-assisted low-dimensional carbon-based electrocatalysts design and mechanism study: a review

“…Adsorption-free energies (ΔG) of key intermediates are utilized as activity descriptors for recognized reactions, including ΔG H for HER ( Han et al, 2023b ), ΔG O for ORR ( Han et al, 2023a ), ΔG CO for CO 2 RR ( Chen et al, 2022a ), and ΔG N for NRR ( Fang et al, 2023 ). For instance, DFT calculations were conducted on the MoS 2 edge, yielding a ΔG H of 0.08 eV, which closely approaches the optimal value of 0 eV ( Hinnemann et al, 2005 ).…”

“…Therefore, the conversion of N 2 to NH 3 under ambient conditions is a promising research area. Recently, electrocatalytic nitrogen reduction reaction (NRR) has attracted increasing research attention because of its obvious advantages such as low energy consumption, reduced reaction temperature, and enhanced productivity ( Li et al, 2016 ; Cui et al, 2018 ; He et al, 2020c ; Liu Y et al, 2021 ; Ruiyi et al, 2021 ; Samal et al, 2021 ; Wang and Mao, 2021 ; Zhou et al, 2022 ; Fang et al, 2023 ; Liu H. et al, 2023 ). Figure 13 shows the possible reaction pathways of the catalytic conversion of N 2 to NH 3 .…”