Exsolution of Iridium Nanoparticles from Perovskite Oxides: searching for More Active and Stable Catalysts for the Production of Green Hydrogen

• Grant number: 23/08460-2
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2024
• End date: April 30, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Pablo Sebastián Fernández
• Grantee: Keyla Teixeira Santos
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Company: Universidade Estadual de Campinas (UNICAMP). Instituto de Química (IQ)
• Associated research grant: 17/11986-5 - Generation and storage of New Energy: bringing technological development for the country, AP.PCPE

Abstract

The escalating global energy demands claims for the exploration of sustainable approaches to energy generation. In this context, green hydrogen (gH2) has emerged as a crucial energy carrier in facilitating the ongoing energy transition. However, the cost-effectiveness of gH2 production faces significant challenges, being one of the most important to speed up the electro-oxidation of water in electrolyzers. Despite substantial research efforts over the past decades, this electrochemical reaction continues to limit the overall efficiency of the hydrogen production process.The Oxygen Evolution Reaction (OER) is considered a bottleneck to the water electro-oxidation process due to its intrinsic kinetic limitations and high energy requirements. The OER typically takes place at catalytic surfaces, which are mandatory to enhance the reaction rate and minimize energy losses. Several catalysts have demonstrated promising OER performance. Among them, transition metal-based oxides, such as Ir, have shown satisfactory OER catalytic activity. However, Ir is a rare and expensive metal and its use for OER presents challenges due to the high cost and limited availability. Therefore, Ir-based materials will be competitive only by maximizing the metal usage and attaining excellent stabilities. In this sense, the exsolution of nanoparticles (NPs) from perovskite oxides (PO) has emerged as a promising strategy for synthesizing stable metal NPs with tunable electronic and catalytic properties and minimizing the use of noble metal.Herein, we will study the electrochemical exsolution of Ir NPs from PO using several ex situ and in situ techniques. Afterward, we will investigate the activity and selectivity of the materials for OER in conventional three-electrode electrochemical cells. Finally, the more promising catalysts in terms of activity and selectivity will be used in a Proton Exchange Membrane (PEM) electrolyzer. Primarily, we will optimize the exsolution process in the device. Subsequently, we will use it to produce gH2 by water electrolysis.