(307a) Discovery of First-Row Transition Metal Antimonates As Efficient Oxygen Electrocatalysts

Water electrolyzers and Hydrogen fuel cells present a promising prospect for transitioning away from carbon-intensive fuels for energy needs. However, the energy efficiencies of these renewable technologies have been hampered by the sluggish kinetics of oxygen-based (oxygen evolution reaction-OER and oxygen reduction reaction-ORR) electrochemical reactions and consequently demand a high overpotential to drive these reactions, even when using state–of–the–art oxygen electrocatalysts.¹ Moreover, the stability of these materials should be on par with its catalytic activity to develop electrocatalysts for practical applications. Therefore, it is imperative to discover and design the next generation of oxygen electrocatalysts that are stable in harsh acidic conditions, active, and affordable.

Herein, we used computational Pourbaix diagrams to identify acid stable non–binary oxide materials by analyzing the aqueous stability of oxides in the Materials Project database² at pH = 0 under typical potential ranges of 0.6 – 1.0 V (vs. SHE) and 1.2 – 2.0 V (vs. SHE) for ORR and OER, respectively. Then we performed a systematic high-throughput screening of the ORR and OER activity of these stable materials to predict theoretical ORR limiting potentials and OER overpotentials. These calculations predicted first-row transition metal antimonates (MSbO_x, M=Mn, Fe, Ni, Co) have desirable ORR and OER performance characteristics.³ Moreover, the effect of introducing transition metals on the activity of these MSbO_x is studied using computational methods and demonstrated the viability of nanoscale ternary and quaternary systems in this family.⁴ Finally, on the basis of theoretical and experimental findings, rational catalyst design principles for next-generation oxygen electrocatalysts are established.

1 Seh, Z. W. et al. Science 355, eaad4998 (2017)

2 Jain, A. et al. APL Materials 1, 011002 (2013)

3 Gunasooriya, G. T. K. K. et al. ACS Energy Lett. 5, 3778–3787 (2020)

4 Kreider, M. E. et al. ACS Catal. 12, 10826–10840 (2022)