(66f) Oxides Supported Transition Metal Single?Atom Catalysts for Oxygen Electrocatalysis

Conversion of electricity into fuels and chemicals is an enabling technology for grid-scale energy storage as renewable energy sources (solar, wind, and hydroelectric) are intermittent. The oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) plays a critical role in such technologies, however, the energy efficiencies of these renewable technologies have been hampered by the sluggish kinetics of OER and ORR 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.[2] Single-atom catalysts (SACs) supported on acid-stable oxides have recently emerged as an important class of electrocatalysts due to the prospects of maximizing the efficiency of precious metal utilization, developing well-defined single-site materials, and as a potential strategy to break or circumvent the scaling relations.

In this work, we selected SnO₂ as an acid-stable oxide host material and considered 29 elements corresponding to 3d, 4d, and 5d transition metals as SACs. We systematically analyzed the stability of these SACs on different locations on the host facets and performed a high-throughput screening of the ORR and OER activity to identify the most promising candidates for experimental validation. Additionally, we use machine learning models to evaluate the activity trends across the 29 SACs using bulk, surface, and atomic type descriptors and identify the most important descriptor of activity. We then provide a generalized framework on the concept of different SAC transition-metals and host metal oxides. Finally, based on theoretical findings, rational catalyst design principles for next-generation oxygen electrocatalysts are established.

[1] Z.W. Seh, J. Kibsgaard, C.F. Dickens, I. Chorkendorff, J.K. Nørskov, T.F. Jaramillo, Science 355 (2017) eaad4998

[2] G.T.K.K. Gunasooriya, J.K. Nørskov, ACS Energy Lett. 5 (2020) 3778–3787