A groundbreaking advancement in the field of electrocatalysis has emerged from a collaborative research effort between Pohang University of Science and Technology (POSTECH) and Seoul National University. The team has successfully developed a novel approach that activates water-splitting catalysts at an unprecedentedly low oven temperature of just 300 °C, a sharp decline from the conventional requirements that exceed 800 °C. This temperature reduction is not merely an energy-saving feat; it also substantially enhances the catalytic performance by increasing oxygen evolution reaction (OER) efficiency by nearly sixfold. Such enhancements promise to redefine the landscape of sustainable hydrogen production, offering an energy-efficient path forward for water electrolysis technologies.
Water electrolysis, a process where electrical energy is used to split water molecules into hydrogen and oxygen gases, holds immense promise as a means to store intermittent energy generated from solar and wind power. Unlike fossil fuels, renewable energy sources produce variable output depending on time and weather conditions, making reliable storage solutions essential. Hydrogen, being a clean and energy-dense carrier, emerges as a crucial pillar in this context. By converting excess electricity into hydrogen through water splitting, energy can be stored over long durations and later retrieved by converting hydrogen back into electricity, ensuring grid stability and continuous power availability.
The oxygen evolution reaction, occurring at the electrode interface of electrolyzers, is a critical and rate-limiting step in this electrochemical process. The sluggish kinetics underpinning OER necessitate a high overpotential, thereby imposing significant energy losses that reduce overall system efficiency. Electrocatalysts are central to mitigating this energy barrier by accelerating the complex, multistep electron-transfer sequences inherent to OER. Research in this area is intensely focused on discovering and engineering catalysts with superior activity, stability, and cost-effectiveness to propel hydrogen production technologies into widespread adoption.
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In their innovative approach, the research team concentrated on perovskite-type materials, a class of oxides noted for their structural stability, compositional versatility, and adaptability for catalytic applications. Perovskites are characterized by their unique crystal lattice structures, which can host various transition metal ions, thus offering tunability in catalytic properties. However, a notable limitation has been the relatively large grain size of these materials—often exceeding 100 nm—which restricts their active surface area and, consequently, their catalytic efficiency.
To address this intrinsic limitation, the scientists employed the exsolution process, whereby transition metal ions are induced to migrate from the bulk lattice of the perovskite material to its surface, forming nanoscale metallic particles. These exsolved nanoparticles act as highly active catalytic sites, dramatically boosting the material’s electrochemical properties. Traditionally, the exsolution effect demands high-temperature treatments above 800 °C sustained for several hours, a factor that significantly elevates manufacturing costs and energy consumption, while also potentially compromising material stability.
The transformative innovation introduced by the researchers involves coupling the exsolution technique with bead milling — a mechanical process that utilizes microscopic beads to physically grind and fragment materials into fine particles. This method not only reduces particle size but also disrupts and loosens the internal structure of the perovskite lattice, facilitating an easier migration path for metal ions toward the surface. By applying bead milling prior to the exsolution treatment, the team achieved efficient exsolution at a remarkably low temperature of 300 °C, thereby circumventing the traditional thermal constraints.
This low-temperature exsolution not only preserves the structural integrity of the perovskite material but also enhances the formation of highly dispersed cobalt nanoparticles on its surface, substantially elevating the catalyst’s activity for oxygen evolution. The resultant electrocatalyst exhibits a nearly sixfold increase in oxygen generation efficiency compared to the unmodified perovskite catalyst. This leap in performance is accompanied by a significant reduction in energy cost and processing time, making the technique attractive for large-scale industrial application aimed at green hydrogen production.
Moreover, the reduced thermal budget of this method has profound implications for sustainability and economic feasibility. High-temperature processes are typically energy-intensive and often demand specialized equipment, increasing capital and operational expenses. By enabling exsolution at lower temperatures, the bead-milling assisted method mitigates these barriers, potentially accelerating the commercialization of high-performance, low-cost water electrolyzers. This advancement aligns with global efforts to develop hydrogen economy infrastructure in pursuit of carbon neutrality.
The study exemplifies how tailoring the nanostructure and surface chemistry of catalyst materials can dramatically influence their kinetic behavior. Professor Yong-Tae Kim, one of the lead investigators, emphasized the importance of nanoscale structural control, suggesting that precision in material design will be pivotal in boosting the efficiency of energy conversion systems. The observed synergy between mechanical and thermal stimuli in the exsolution process opens new avenues for catalyst engineering beyond conventional thermal treatments.
The research also underscores the strategic selection of cobalt as the active metal ion undergoing exsolution. Cobalt-based catalysts are known for their high catalytic activity and reasonable abundance, balancing performance and material cost. Embedding cobalt in a perovskite matrix and finely tuning its surface exposure addresses previous challenges related to catalyst durability and cost, positioning this technology as a viable candidate for next-generation electrolyzer systems.
Supporting this innovative work, funding was provided by the Ministry of Science and ICT through programs such as H2NEXTROUND and the Nano Materials Technology Development Program, highlighting the strategic national interest in advancing hydrogen technologies. The collaborative nature of the study, bringing together expertise from instrumentation, materials science, and electrochemistry, illustrates the multidisciplinary efforts required to tackle pressing energy challenges.
Published as the cover article in the July 17th issue of Advanced Functional Materials, this research not only demonstrates scientific excellence but also sets a benchmark for future investigations into sustainable catalyst manufacturing processes. By harmonizing materials science, mechanical processing, and electrochemical engineering, the team has laid foundational work for scalable, energy-efficient production of electrocatalysts crucial to hydrogen economies.
In summary, this pioneering low-temperature exsolution method enabled by bead milling marks a remarkable leap forward in water-splitting technology. It not only slashes the thermal demands traditionally associated with catalyst activation but concurrently amplifies catalytic efficiency. Such innovations pave the way for more economical and environmentally sustainable technologies, bringing the vision of large-scale green hydrogen production and storage closer to reality. As the global community intensifies its decarbonization efforts, breakthroughs like this could play transformative roles in reshaping energy infrastructures worldwide.
Subject of Research:
Low-temperature activation of perovskite electrocatalysts for enhanced oxygen evolution reaction in water electrolysis.
Article Title:
Low-Temperature Exsolution of Cobalt From Perovskite Nanoparticles via Bead Milling for Enhanced Electrocatalytic Oxygen Evolution Reaction
News Publication Date:
17-Jul-2025
Web References:
http://dx.doi.org/10.1002/adfm.202506227
Image Credits:
POSTECH
Keywords
Applied sciences and engineering; Perovskites; Electrolysis; Water splitting; Water electrolysis; Chemistry; Electrochemistry; Electrochemical deposition; Materials; Metals; Catalysis
Tags: electrocatalysis advancementsenergy-efficient water electrolysis technologiesenhanced catalyst performancehydrogen as clean energy carrierinnovative approaches in renewable energylow-temperature water-splittingoven-temperature treatment for catalystsoxygen evolution reaction efficiencyPOSTECH and Seoul National University collaborationreducing energy consumption in catalysisrenewable energy storage solutionssustainable hydrogen production methods