Issue 39, 2019

Single molybdenum atom anchored on 2D Ti2NO2 MXene as a promising electrocatalyst for N2 fixation

Abstract

The electrocatalytic synthesis of ammonia (NH3) at ambient temperature is an attractive and challenging subject in the chemical industry. The synthesis of NH3 under ambient conditions requires efficient and stable electrocatalysts with ultralow overpotential to ensure low energy consumption and high NH3 yield. Herein, electrocatalysts consisting of a single transition metal (TM) atom (TM = Mo, Mn, Fe, Co, Ni, or Cu) anchored on 2D M2NO2 MXene (M = Ti, V, and Cr), designated as TM/M2NO2, are designed for N2 reduction reaction (NRR) by density functional theory calculations. The results show that the bonding strength between Mo and Ti2NO2 is strong. The overpotential (ηNRR) of Mo/Ti2NO2 surface-catalyzed NRR is estimated to be as low as 0.16 V via an enzymatic mechanism, which is lower than those reported to date. For Mo/V2NO2 and Mo/Cr2NO2 catalysts, the NRR occurs through the consecutive mechanism and enzymatic mechanism, with corresponding ηNRR values of 0.38 V and 0.22 V, respectively. In addition, the reaction Gibbs free energy of NH3 desorption from the Mo/Ti2NO2 surface is only 0.12 eV. Electronic structure analysis indicates that Mo/Ti2NO2 shows metallic characteristics, which ensures the efficient transfer of electrons between Mo and Ti2NO2. Ab initio molecular dynamics simulations indicate that the Mo atom can be stably immobilized on the Ti2NO2 substrate to prevent its aggregation into Mo clusters. Further analysis illustrates that hydrogen adsorption is not favored on the Mo/Ti2NO2 surface. Mixing the N2 source with extra gases, such as NO2, NO, SO2, SO, and O2, should be avoided for NRR on Mo/Ti2NO2 surface. These predictions offer a new opportunity for the electrocatalytic synthesis of NH3 by N2 reduction in the future.

Graphical abstract: Single molybdenum atom anchored on 2D Ti2NO2 MXene as a promising electrocatalyst for N2 fixation

Supplementary files

Article information

Article type
Paper
Submitted
26 Jun 2019
Accepted
11 Sep 2019
First published
11 Sep 2019

Nanoscale, 2019,11, 18132-18141

Single molybdenum atom anchored on 2D Ti2NO2 MXene as a promising electrocatalyst for N2 fixation

Y. Cheng, J. Dai, Y. Song and Y. Zhang, Nanoscale, 2019, 11, 18132 DOI: 10.1039/C9NR05402B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements