First-Row Transition Metal Antimonates for the Oxygen Reduction Reaction

G T Kasun Kalhara Gunasooriya; Melissa E Kreider; Yunzhi Liu; José A Zamora Zeledón; Zhenbin Wang; Eduardo Valle; An-Chih Yang; Alessandro Gallo; Robert Sinclair; Michaela Burke Stevens; Thomas F Jaramillo; Jens K Nørskov

doi:10.1021/acsnano.2c00420

First-Row Transition Metal Antimonates for the Oxygen Reduction Reaction

ACS Nano. 2022 Apr 26;16(4):6334-6348. doi: 10.1021/acsnano.2c00420. Epub 2022 Apr 4.

Authors

G T Kasun Kalhara Gunasooriya¹, Melissa E Kreider^{2

3}, Yunzhi Liu⁴, José A Zamora Zeledón^{2

3}, Zhenbin Wang¹, Eduardo Valle^{2

3}, An-Chih Yang^{2

3}, Alessandro Gallo^{2

3}, Robert Sinclair⁴, Michaela Burke Stevens^{2

3}, Thomas F Jaramillo^{2

3}, Jens K Nørskov¹

Affiliations

¹ Catalysis Theory Center, Department of Physics, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
² Department of Chemical Engineering, Stanford University, 443 via Ortega, Stanford, California 94305, United States.
³ SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States.
⁴ Department of Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305, United States.

PMID: 35377139
DOI: 10.1021/acsnano.2c00420

Abstract

The development of inexpensive and abundant catalysts with high activity, selectivity, and stability for the oxygen reduction reaction (ORR) is imperative for the widespread implementation of fuel cell devices. Herein, we present a combined theoretical-experimental approach to discover and design first-row transition metal antimonates as excellent electrocatalytic materials for the ORR. Theoretically, we identify first-row transition metal antimonates─MSb₂O₆, where M = Mn, Fe, Co, and Ni─as nonprecious metal catalysts with good oxygen binding energetics, conductivity, thermodynamic phase stability, and aqueous stability. Among the considered antimonates, MnSb₂O₆ shows the highest theoretical ORR activity based on the 4e^- ORR kinetic volcano. Experimentally, nanoparticulate transition metal antimonate catalysts are found to have a minimum of a 2.5-fold enhancement in intrinsic mass activity (on transition metal mass basis) relative to the corresponding transition metal oxide at 0.7 V vs RHE in 0.1 M KOH. MnSb₂O₆ is the most active catalyst under these conditions, with a 3.5-fold enhancement on a per Mn mass activity basis and 25-fold enhancement on a surface area basis over its antimony-free counterpart. Electrocatalytic and material stability are demonstrated over a 5 h chronopotentiometry experiment in the stability window identified by theoretical Pourbaix analysis. This study further highlights the stable and electrically conductive antimonate structure as a framework to tune the activity and selectivity of nonprecious metal oxide active sites for ORR catalysis.

Keywords: Pourbaix diagram; catalyst design; electrocatalysis; fuel cells; nonprecious metal catalysts; oxygen reduction reaction; transition metal antimonates.