Researchers led by Gang Wu, the Elvera and William R. Stuckenberg Professor in the McKelvey School of Engineering at Washington University in St. Louis, have developed a nanostructured carbon support that enables the production of highly durable, high-performance platinum-cobalt catalysts. The material consists of hollow carbon spheres containing ordered nanochannels that extend outward in a radial pattern. These channels act as a precisely engineered framework for stabilizing tiny metallic particles during the extreme heat needed to create an ordered intermetallic structure.

Fuel cells generate electricity through electrochemical reactions rather than combustion. In a hydrogen fuel cell, hydrogen is oxidized at the anode, while oxygen is reduced at the cathode. The reactions produce electricity, water and heat, but they rely on catalysts to accelerate the chemical processes and reduce energy losses. Platinum is exceptionally effective for these reactions, especially the oxygen reduction reaction at the cathode, but it is expensive, scarce and vulnerable to gradual degradation during operation. The central challenge is therefore to maximize platinum’s activity while using as little of the precious metal as possible.

Reducing platinum to nanoparticles increases the amount of surface area available for chemical reactions. Fuel-cell electrodes can achieve high catalytic performance with platinum loadings of less than one-quarter of a milligram per square centimeter. However, the small particles can dissolve, migrate across the electrode or merge into larger particles under operating conditions. This process, known as coarsening or agglomeration, reduces the active surface area and progressively lowers fuel-cell performance. A catalyst that is highly active at the beginning of its life may therefore lose much of its effectiveness after extended use.

Platinum intermetallic compounds, in which platinum atoms combine with another metal in a highly ordered crystal arrangement, offer a promising solution. Platinum-cobalt materials can display improved catalytic activity and greater resistance to degradation compared with conventional platinum alloys. Creating the desired ordered structure generally requires annealing at temperatures below about 700 degrees Celsius to prevent nanoparticles from growing too large. Yet those temperatures may be insufficient to complete the order-disorder transition required to achieve the most favorable atomic arrangement. Higher temperatures improve ordering but typically cause nanoparticles to merge, creating the classic conflict between activity and stability.

Wu’s team addressed this problem by designing carbon spheres with hollow interiors, high surface areas and radial nanochannels whose dimensions and pore volumes can be carefully controlled. The channels provide physical confinement for the platinum-cobalt particles, keeping them separated while allowing the material to withstand much higher processing temperatures. Using this support, the researchers heated the catalyst to 1,000 degrees Celsius, a temperature high enough to produce a strongly ordered intermetallic phase while maintaining particle sizes below 5 nanometers.

The result is a catalyst that combines the advantages of very small particles with the stability of a highly organized atomic structure. The carbon framework holds the platinum-cobalt nanoparticles in place and prevents them from undergoing severe growth during high-temperature treatment. At the same time, the open pore network exposes the catalyst to reactants and creates pathways through which protons, oxygen and water can move within the electrode. This transport architecture is particularly important because fuel-cell performance depends not only on the intrinsic activity of the catalyst but also on how efficiently gases, ions and liquid water reach the reaction sites.

The researchers reported that the catalyst retained approximately 85% of its initial performance after 150,000 voltage cycles, a demanding durability test that may correspond to roughly 25,000 hours of operation. The combination of ordered intermetallic nanoparticles, high platinum utilization and accessible carbon channels produced what the team described as best-in-class activity and durability. The architecture also permits the ionomer, the proton-conducting material used in fuel-cell electrodes, to distribute more evenly throughout the porous structure. Better ionomer placement can reduce transport barriers and help maintain electrochemical activity during prolonged use.

The technology could eventually support fuel cells for stationary power, including electricity generation at data centers, as well as transportation and other applications requiring efficient energy conversion. Fuel cells can convert hydrogen and other fuels directly into electricity, potentially reducing pressure on electrical grids when paired with low-carbon hydrogen or renewable fuels. The researchers emphasize that further development, scale-up and industrial collaboration will be necessary before the catalyst can be deployed commercially. Wu has filed a patent through the Washington University Office of Technology Management. The study, conducted with collaborators from Brookhaven National Laboratory, Lawrence Berkeley National Laboratory, Northeastern University and the University of Pittsburgh, was published in Nature Nanotechnology on Aug. 6, 2026.

Subject of Research: High-performance platinum-cobalt intermetallic nanoparticle catalysts supported by radial nanochannel-array carbon for durable fuel cells.

Article Title: Radial nanochannel-array carbon enables high-performance intermetallic fuel cell catalysts.

News Publication Date: 6-Aug-2026

Web References: https://doi.org/10.1038/s41565-026-02244-8; https://engineering.washu.edu/faculty/Gang-Wu.html

References: Gao L, Hwang S, Li X, Zheng J, Lee K, Liu S, Wierzbicki D, Li J, Guo J, Zhang B, Lin H, Zhao Q, Wang G, Dun C, Wu G. “Radial nanochannel-array carbon enables high-performance intermetallic fuel cell catalysts.” Nature Nanotechnology, Aug. 6, 2026. DOI: 10.1038/s41565-026-02244-8.

Image Credits: Wu lab, Washington University in St. Louis.

Keywords

Fuel cells, hydrogen energy, platinum catalysts, platinum-cobalt nanoparticles, intermetallic catalysts, nanocarbon, radial nanochannels, carbon supports, clean energy, data centers, renewable energy, electrochemistry, catalyst durability, fuel-cell technology.

The crux of enhancing ORR electrocatalysts lies in balancing catalytic activity with economic viability. Traditional Pt-based catalysts, although highly efficient, suffer from scarcity and expense. Consequently, researchers have pivoted toward engineered composites that synergistically combine platinum with earth-abundant transition metals and nitrogen-doped carbon frameworks to optimize catalytic efficiency whilst slashing platinum content. The latest breakthrough employs a Fe-N-C substrate meticulously synthesized via a polyaniline (PANI) templating process to achieve atomic-scale distribution and coordination of iron-nitrogen sites. This precise structural tailoring primes the material to not only support but actively enhance platinum incorporation at minimal loadings.

The synthesis mechanism utilizes the inherent advantages of polyaniline chemistry, enabling the synthesis of well-defined Fe-N-C precursors characterized by rich nitrogen coordination environments. These sites uniformly anchor platinum ions during subsequent adsorption steps, encouraging the formation of Pt-Fe bimetallic alloys. Such alloying induces a remarkable electronic interplay between platinum atoms and the Fe-N-C support structure, generating modified electronic states favorable for catalytic turnover. This interaction promotes excellent dispersion of platinum nanoparticles, drastically reducing their size to nanoscale clusters with increased surface area and accessible active sites—features essential for superior catalytic performance.

Electrochemical evaluations of the resulting Pt/Fe-N-C catalyst reveal a transformative leap in ORR kinetics. Operating at an ultra-low platinum loading of approximately 1.79 wt%, the catalyst exhibits a doubling of mass activity relative to conventional Pt-based systems. This improvement signifies not just an incremental gain but a paradigm shift, demonstrating that carefully engineered synergistic effects can compensate for—and indeed surpass—traditional platinum demands. Such enhanced intrinsic catalytic activity substantially lowers precious metal usage without trade-offs in performance, which could reshape budget considerations for clean energy technologies.

Beyond activity, catalyst stability is paramount for practical applications. The Pt/Fe-N-C system demonstrates exceptional durability under stringent testing conditions. In alkaline media, the half-wave potential registers a marginal decline of only 20 millivolts even after enduring 10,000 electrochemical cycles, underscoring robust resistance to typical degradation pathways such as nanoparticle agglomeration or detachment. In acidic electrolytes, the catalyst maintains virtually unaltered half-wave potentials over equivalent cycling, an indicator of formidable chemical resilience, crucial for varied fuel cell environments. These findings confirm the capability of the catalyst to sustain high performance during prolonged operational periods.

The implications of these advancements extend notably to zinc-air battery technology. Within this domain, the Pt/Fe-N-C catalyst delivers a peak power density of 200 milliwatts per square centimeter, a substantial milestone surpassing many existing benchmarks. Such robust power output at reduced platinum content translates directly into cost-effective, high-capacity energy storage solutions. Moreover, the catalyst’s ability to retain activity and structural integrity after extensive cycling promises enhanced battery lifetimes, addressing key commercial viability concerns that have so far hindered widespread deployment.

From a mechanistic perspective, the enhanced ORR activity originates from the intricate synergy between Pt and Fe-N-C catalytic sites. The Fe-N-C matrix not only stabilizes the platinum nanoparticles but also modulates electron density, tuning adsorption energies for oxygen intermediates to favor the reaction pathway. This dual-site cooperative effect facilitates faster reaction kinetics and improves selectivity towards the desirable four-electron reduction process, minimizing undesired peroxide formation and enhancing overall efficiency. Such molecular-level insight underpins the rational design of next-generation catalysts.

This investigation also underscores the critical role of nanoengineering in catalyst design. By controlling not only the composition but also the spatial arrangement and particle size distribution of active sites, the researchers effectively optimize surface chemistry and electronic structure. The polyaniline-mediated fabrication process specifically enables scalable and reproducible production of catalysts with uniformly dispersed bimetallic sites, essential for translating laboratory discoveries into commercial-scale manufacturing.

The reported breakthroughs align with the broader global imperative to decarbonize energy systems sustainably. Fuel cells and metal-air batteries, empowered by cutting-edge catalysts such as Pt/Fe-N-C, are poised to become cornerstones of clean energy infrastructure. The reduction in platinum usage directly addresses cost and supply challenges, opening avenues for the deployment of affordable, high-efficiency fuel cells in transportation, portable electronics, and grid storage applications. Concurrently, improved zinc-air batteries could revolutionize how intermittent renewable energy sources are buffered and delivered with minimal environmental impact.

In summary, the development of an ultra-low platinum loading ORR electrocatalyst integrating platinum with Fe-N-C support exemplifies a significant stride toward next-generation energy conversion technologies. The fusion of elaborate synthetic chemistry, precise nanostructuring, and insightful mechanistic understanding culminates in a catalyst that excels in activity, stability, and cost-effectiveness. As these materials enter further stages of validation and commercialization, they hold promise to transform the sustainable energy landscape, addressing longstanding limitations of precious metal dependency and propelling fuel cell and battery technologies into more widespread use.

This study not only elevates the benchmark for catalyst performance but also charts a strategic framework for future innovations. The approach of leveraging synergistic interactions between noble metals and engineered supports could be extended to other catalytic challenges beyond ORR, including hydrogen evolution and carbon dioxide reduction. Such versatility and scalability will be critical in meeting the diverse demands of a decarbonized global economy, fostering resilient and adaptable energy solutions for decades to come.

Researchers and industry stakeholders alike are now poised to capitalize on these findings, exploring integration avenues within full-cell configurations and pilot-scale deployments. Ongoing efforts will likely focus on refining synthesis protocols, optimizing electrode architectures, and enhancing compatibility with diverse operating conditions. Collectively, these advancements signal a transformative era in electrocatalysis, where materials design, sustainability, and performance converge to realize the full potential of renewable energy technologies.

Subject of Research: Not applicable

Article Title: An ultra-low platinum loading ORR electrocatalyst with high efficiency: Synergistic effects of Pt and Fe-N-C support

News Publication Date: 28-Apr-2025

Web References: 10.1007/s11708-025-1006-4

Image Credits: HIGHER EDUCATION PRESS

Keywords

Energy