Elucidating electrochemical nitrate and nitrite reduction over atomically-dispersed transition metal sites

Eamonn Murphy; Yuanchao Liu; Ivana Matanovic; Martina Rüscher; Ying Huang; Alvin Ly; Shengyuan Guo; Wenjie Zang; Xingxu Yan; Andrea Martini; Janis Timoshenko; Beatriz Roldán Cuenya; Iryna V Zenyuk; Xiaoqing Pan; Erik D Spoerke; Plamen Atanassov

doi:10.1038/s41467-023-40174-4

Elucidating electrochemical nitrate and nitrite reduction over atomically-dispersed transition metal sites

Nat Commun. 2023 Jul 28;14(1):4554. doi: 10.1038/s41467-023-40174-4.

Authors

Eamonn Murphy^#¹, Yuanchao Liu^#¹, Ivana Matanovic^{2

3}, Martina Rüscher⁴, Ying Huang⁵, Alvin Ly⁵, Shengyuan Guo¹, Wenjie Zang⁵, Xingxu Yan⁵, Andrea Martini⁴, Janis Timoshenko⁴, Beatriz Roldán Cuenya⁴, Iryna V Zenyuk^{1

5}, Xiaoqing Pan⁵, Erik D Spoerke⁶, Plamen Atanassov^{7

8}

Affiliations

¹ Department of Chemical and Biomolecular Engineering, University of California, Irvine, CA, 92697, USA.
² Department of Chemical and Biological Engineering, University of New Mexico, Albuquerque, NM, 87131, USA.
³ Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
⁴ Department of Interface Science, Fritz Haber Institute of the Max Planck Society, 4-6 Faradayweg, Berlin, 14195, Germany.
⁵ Department of Materials Science and Engineering, University of California, Irvine, CA, 92697, USA.
⁶ Sandia National Laboratories, Albuquerque, NM, 87185, USA.
⁷ Department of Chemical and Biomolecular Engineering, University of California, Irvine, CA, 92697, USA. plamen.atanassov@uci.edu.
⁸ Department of Materials Science and Engineering, University of California, Irvine, CA, 92697, USA. plamen.atanassov@uci.edu.

^# Contributed equally.

Abstract

Electrocatalytic reduction of waste nitrates (NO₃^-) enables the synthesis of ammonia (NH₃) in a carbon neutral and decentralized manner. Atomically dispersed metal-nitrogen-carbon (M-N-C) catalysts demonstrate a high catalytic activity and uniquely favor mono-nitrogen products. However, the reaction fundamentals remain largely underexplored. Herein, we report a set of 14; 3d-, 4d-, 5d- and f-block M-N-C catalysts. The selectivity and activity of NO₃^- reduction to NH₃ in neutral media, with a specific focus on deciphering the role of the NO₂^- intermediate in the reaction cascade, reveals strong correlations (R=0.9) between the NO₂^- reduction activity and NO₃^- reduction selectivity for NH₃. Moreover, theoretical computations reveal the associative/dissociative adsorption pathways for NO₂^- evolution, over the normal M-N₄ sites and their oxo-form (O-M-N₄) for oxyphilic metals. This work provides a platform for designing multi-element NO₃RR cascades with single-atom sites or their hybridization with extended catalytic surfaces.

Grants and funding

AOP-34920/DOE | Office of Energy Efficiency and Renewable Energy (Office of Energy Efficiency & Renewable Energy)