The development of efficient and durable catalysts for the kinetically sluggish oxygen evolution reaction (OER) is paramount for advancing various electrochemical processes including water splitting, CO2 electroreduction, and metal air batteries. In this presentation, the synthesis, characterization, and electrochemical evaluation of monometallic, bimetallic, and trimetallic transition metal OER catalysts will be discussed. We employed a colloidal synthesis approach to fabricate mesoporous oxyphosphide catalysts with varying compositions. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterization revealed the formation of a distinct core@shell structure comprising a zero-valent metallic core enveloped by a porous oxygen-rich shell. An OER potential of <1.5 V versus RHE at 10 mA cm-2 and a low Tafel slope of 32 mV decade-1 were measured, surpassing other catalyst configurations including commercial platinum-group-metal-free (PGM-free) catalysts in alkaline media. Furthermore, excellent OER durability at 10 mA cm-2 was demonstrated, with a potential increase of <0.5 mV/h after 100 hours of testing. These findings underscore the potential of TM oxyphosphide catalysts as promising candidates for efficient and durable OER electrocatalysts, paving the way for sustainable energy conversion and storage technologies.AcknowledgmentsThis work was supported by the U.S. Department of Energy (DOE), Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office (HFTO) under the auspices of the Electrocatalysis Consortium (ElectroCat 2.0). Argonne is managed for the U.S Department of Energy by the University of Chicago Argonne, LLC, under Contract DE-AC-02-06CH11357. Khalafallah D, Farghaly AA, Ouyang C, Huang W, Hong Z. Atomically dispersed Pt single sites and nanoengineered structural defects enable a high electrocatalytic activity and durability for hydrogen evolution reaction and overall urea electrolysis. Journal of Power Sources. 2023, 558, 232563.Onajah S, Sarkar R, Islam MS, Lalley M, Khan K, Demir M, Abdelhamid HN, Farghaly AA. Silica‐Derived Nanostructured Electrode Materials for ORR, OER, HER, CO2RR Electrocatalysis, and Energy Storage Applications: A Review. The Chemical Record. 2024, e202300234.Sarkar R, Farghaly AA, Arachchige IU. Oxidative Self-Assembly of Au/Ag/Pt Alloy Nanoparticles into High-Surface Area, Mesoporous, and Conductive Aerogels for Methanol Electro-oxidation. Chemistry of Materials. 2022, 34(13), 5874-87.
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