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University of Belgrade - Institute of Chemistry, Technology and Metallurgy - National Institute of the Republic of Serbia, Department of Electrochemistry, Njegoševa 12 , Belgrade , Serbia
Center of Excellence in Environmental Chemistry and Engineering, Institute of Chemistry, Technology and Metallurgy, Njegoševa 12 , Belgrade , Serbia
University of Belgrade - Institute of Chemistry, Technology and Metallurgy - National Institute of the Republic of Serbia, Department of Electrochemistry, Njegoševa 12 , Belgrade , Serbia
University of Belgrade - Institute of Chemistry, Technology and Metallurgy - National Institute of the Republic of Serbia, Department of Electrochemistry, Njegoševa 12 , Belgrade , Serbia
Center of Excellence in Environmental Chemistry and Engineering, Institute of Chemistry, Technology and Metallurgy, Njegoševa 12 , Belgrade , Serbia
University of Belgrade, Innovation Center of Faculty of Technology and Metallurgy, Karnegijeva 4 , Belgrade , Serbia
University of Belgrade - Institute of Chemistry, Technology and Metallurgy - National Institute of the Republic of Serbia, Department of Electrochemistry, Njegoševa 12 , Belgrade , Serbia
Center of Excellence in Environmental Chemistry and Engineering, Institute of Chemistry, Technology and Metallurgy, Njegoševa 12 , Belgrade , Serbia
State University of Novi Pazar,Vuka Karadžića bb , Novi Pazar , Serbia
University of Belgrade - Institute of Chemistry, Technology and Metallurgy - National Institute of the Republic of Serbia, Department of Electrochemistry, Njegoševa 12 , Belgrade , Serbia
Center of Excellence in Environmental Chemistry and Engineering, Institute of Chemistry, Technology and Metallurgy, Njegoševa 12 , Belgrade , Serbia
University of Belgrade, Innovation Center of Faculty of Technology and Metallurgy, Karnegijeva 4 , Belgrade , Serbia
The consecutive microwave-assisted hydrothermal shelling combined with aerosol-assisted calcination was applied as a synthesis route for IrO2-shelled CoCeY oxide core composites, designed as potential high-efficiency catalysts for the oxygen evolution reaction (OER) with a reduced iridium content. The search for such efficient OER catalysts is of great significance in advancing metal-air rechargeable batteries and hydrogen production via water electrolysis, where minimizing the use of costly noble metals remains a critical challenge. CoCeY oxide supports were synthesized using a one-step ultrasonic spray pyrolysis (USP) process, in which precursor aqueous solutions of CeCl3, Y(NO3)3, and Co(NO3)2 were mixed in mole ratios of Ce:Y:Co = 8:2:5 and Ce:Y:Co = 2:8:5. The USP process was carried out under precisely controlled conditions, with the conversion temperature carefully maintained using a thermostated furnace to achieve uniform particle formation and a well-defined phase composition. Nebulization and aerosol generation took place in an oxygen-rich atmosphere, with a regulated gas flow rate of 2 dm3 min⁻1, while the synthesis temperature was consistently held at 800 °C. These parameters enabled the development of CoCeY (∑M) composite structures with the required crystallinity and morphology, providing a stable and suitable framework for further catalyst modification. After the synthesis of oxide supports, the materials were subjected to microwave hydrothermal treatment in the presence of IrCl3 while maintaining a stable temperature, resulting in composite structures with tailored IrO2 mole ratios (∑M:Ir = 3:7 and ∑M:Ir = 7:3). The catalytic performance of the synthesized thin-layer composites for OER was assessed through polarization measurements in acidic media. Electrochemical structure-activity relationships were further examined using impedance spectroscopy, providing insights into charge transfer properties and interfacial kinetics. Additionally, the impact of post-synthesis thermal treatment on the structural and electrochemical properties of the composites was investigated. A strong correlation between structural parameters, physicochemical state, composition, and OER activity was identified, offering valuable guidance for the design of advanced, cost-effective electrocatalysts.
oxygen evolution activity, anode durability, water splitting, activity distribution through bulk powders
Authors wish to acknowledge the support of the Science Fund of the Republic of Serbia PROJECT NUMBER 6666, Renewal of the Waste Oxygen-Evolving anodes from Hydrometallurgy and their improved Activity for Hydrogen Economy, Wastewater and Soil Remediation - OxyRePair.
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