Electrolyzers split water into hydrogen and oxygen using two complementary half-reactions: the hydrogen evolution reaction (HER) at the cathode, where protons or water molecules are reduced to hydrogen gas, and the oxygen evolution reaction (OER) at the anode, a slower, more energy-demanding four-electron process that liberates oxygen. The efficiency losses in a practical electrolyzer stem largely from the overpotentials—excess voltage beyond thermodynamic minimum—needed to push these reactions at useful rates. Platinum and iridium oxide are the standard benchmarks for HER and OER respectively, but their scarcity and cost make them poor candidates for gigawatt-scale hydrogen production. Bifunctional catalysts that can perform both reactions allow a single material to serve as both the cathode and the anode in a two-electrode cell, simplifying device design and cutting costs dramatically.

The new material, designated Ni₁Co₃@CN-sh, was synthesized through a straightforward pyrolysis route. The researchers, led by Muxi Wang, Wenwen Luo, Guang Li, and Qingfeng Yi of Hunan University of Science and Technology, together with Ruowei Yi of Xiangtan University, modulated two key variables: the nickel-to-cobalt ratio in the metallic nanoparticles and the choice of organic compound used as the carbon source. By carefully tuning these parameters, they produced a catalyst in which NiCo alloy nanoparticles are dispersed on flaky, nitrogen-containing carbon sheets that assemble into a three-dimensional hierarchical porous architecture. This porous structure is not merely cosmetic; it provides an abundance of electrochemically accessible active sites, channels for rapid electrolyte penetration, and interconnected pathways for the electrons that must shuttle between the metal particles and the external circuit during catalysis.

The performance numbers reported for the optimal composition are striking. For the oxygen evolution reaction—widely considered the bottleneck of water electrolysis—the Ni₁Co₃@CN-sh catalyst required an overpotential of just 191 millivolts to reach a current density of 100 milliamperes per square centimeter, a figure that places it on par with commercial iridium dioxide, the noble-metal reference catalyst for OER. On the hydrogen side, the same material needed only 194 millivolts of overpotential, comparable to what commercial platinum-on-carbon delivers. Achieving such balanced performance from a single non-noble-metal catalyst is rare, because the atomic-scale requirements for the two reactions differ: HER favors surfaces with optimal hydrogen adsorption energy, while OER depends on the energetics of oxygen-containing intermediates and often benefits from in-situ surface reconstruction into higher-valent oxyhydroxide species.

Nickel and cobalt, as neighboring transition metals, offer a productive synergy that the authors exploited through composition control. Cobalt-rich compositions appear to optimize the electronic structure of the alloy nanoparticles, modulating the d-band position and thereby tuning adsorption energies for reaction intermediates on both catalyst surfaces. The nitrogen-doped carbon support contributes in its own right: graphitic and pyridinic nitrogen sites can tune the electronic structure of adjacent metal atoms, enhance charge transfer, and themselves contribute catalytic activity, while the flaky morphology of the carbon provides mechanical robustness and good electrical connectivity to the metal nanoparticles. The team characterized the material using a comprehensive suite of techniques including X-ray diffraction, scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller surface area analysis, building a structural picture consistent with well-dispersed alloy particles anchored within the conductive carbon framework.

The true test of any electrolysis catalyst comes when it is assembled into a working device, and here the results were particularly compelling. In a two-electrode alkaline electrolyzer with identical Ni₁Co₃@CN-sh electrodes serving as both cathode and anode, the cell required a voltage of only 1.796 volts to sustain a current density of 100 milliamperes per square centimeter. That figure outperformed a reference electrolyzer built from the noble-metal combination of platinum-on-carbon and iridium dioxide, a benchmark pairing that has defined the state of the art for decades. In the economics of water electrolysis, every hundredth of a volt saved at high current density translates directly into lower electricity consumption per kilogram of hydrogen, so an earth-abundant catalyst beating the noble-metal standard at this level is a meaningful milestone.

Perhaps the most industrially relevant finding concerns durability. Alkaline water electrolysis (AWE) is the most mature electrolysis technology, but pushing it toward industrial relevance requires operation at elevated temperatures and very high current densities—conditions that corrode, dissolve, or delaminate most laboratory catalysts within hours. The Hunan team subjected their electrolyzer to 80 degrees Celsius and a current density of 500 milliamperes per square centimeter, a regime approaching that of commercial alkaline electrolyzers. The cell held a voltage of approximately 1.84 volts for more than 200 hours of continuous operation without significant degradation. Sustained stability at 500 milliamperes per square centimeter is a demanding criterion that many highly active catalysts fail, as high current densities accelerate gas bubble formation, catalyst dissolution, and mechanical stress. Surviving this treatment suggests the carbon-supported architecture provides genuine structural resilience rather than just transient high activity.

The design strategy behind the material may prove as important as the catalyst itself. Rather than relying on complex multi-step syntheses or exotic compositions, the researchers demonstrated that systematically varying the bimetallic ratio and carbon precursor in a single pyrolysis step can systematically optimize the three-dimensional pore structure and, with it, catalytic performance. This gives the approach a clear route toward scale-up: pyrolysis of organic-metal precursors is among the simplest and most manufacturable methods for producing carbon-supported nanoparticle catalysts, and the use of nickel and cobalt—both produced in enormous quantities for batteries and steels—avoids the supply-chain fragility associated with platinum-group metals. The study also aligns with a broader trend in electrocatalysis research, where single materials must serve multiple functions, whether HER and OER in electrolyzers or the oxygen reduction and oxygen evolution reactions in rechargeable metal-air batteries.

There remain, of course, gaps between a laboratory electrode and a commercial electrolyzer stack. The researchers evaluated the catalyst on laboratory-scale electrodes in alkaline solution; industrial devices must maintain such performance over months and years, across thousands of start-stop cycles, and at even higher current densities with efficient gas separation. Faradaic efficiency, turnover frequency, and the precise identity of the active sites under operating conditions—particularly the surface species formed during OER—will require further study. The authors also note that no datasets beyond those in the paper were generated, meaning the conclusions rest on the experimental characterization presented. Still, the combination of noble-metal-matching activity, single-material bifunctionality, and demonstrated stability under elevated-temperature, high-current operation places this catalyst among the more practically oriented non-precious systems reported to date.

The work was supported by the National Natural Science Foundation of China under grant number 22379042, and the authors declare no competing interests. As governments worldwide commit to green hydrogen targets and electrolyzer manufacturing ramps up, the search for catalysts that are cheap, active, and durable intensifies. This study offers a promising answer on all three fronts: a nickel-cobalt alloy on flaky nitrogen-doped carbon that splits water as efficiently as precious metals and keeps doing so where it matters—at high current density, high temperature, and for hundreds of hours on end. If the design strategy transfers from alkaline laboratory cells to industrial electrolyzer hardware, earth-abundant catalysts of this kind could play a significant role in making hydrogen a genuinely affordable clean energy carrier.

Hydrogen, as a clean fuel, holds enormous potential to supplant fossil fuels in various sectors ranging from transportation to industrial processes. However, the widespread adoption of hydrogen technology has been limited by challenges in its production, storage, and distribution. Conventional methods often involve high energy inputs or the use of costly and scarce noble metals such as palladium, platinum, or rhodium, which act as catalysts to facilitate hydrogen generation reactions. These constraints have fueled a vigorous search for alternative catalytic systems that can achieve comparable efficiency but reduce costs and improve availability.

The innovative research presented here revolves around thermal catalytic decomposition of formic acid (HCOOH), a promising hydrogen carrier because it can liquefy under mild conditions, is non-toxic, and possesses high hydrogen content by weight. Formic acid naturally breaks down into hydrogen (H₂) and carbon dioxide (CO₂) under suitable catalytic and thermal conditions. Yet, unlocking this reaction with catalysts that avoid precious metals has been an elusive target until now. The team’s approach addresses this by designing a heterogeneous catalyst system composed of earth-abundant elements that can drive the reaction efficiently at relatively low temperatures.

Central to the breakthrough is the use of a tailored catalytic material that balances intrinsic activity with structural stability. Unlike homogeneous catalysts that dissolve in reaction media, these heterogeneous catalysts remain solid and allow for straightforward separation and reuse, a critical feature for industrial application. This catalyst development leans on comprehensive materials science insights, incorporating transition metals integrated within specific supports that optimize surface adsorption and reaction pathways for formic acid decomposition.

From a mechanistic standpoint, the catalytic cycle involves adsorption of formic acid molecules onto the catalyst surface, followed by facilitated breaking of C-H and O-H bonds. Detailed spectroscopic studies and kinetic analyses presented illuminate how the catalyst’s surface sites selectively promote dehydrogenation (releasing hydrogen and CO₂) rather than dehydration (which produces CO and water, an undesired side reaction). This selectivity is paramount since CO contaminates hydrogen fuel cells and impairs their function.

Thermal parameters have been finely tuned, with experiments demonstrating that moderate temperature ranges—significantly lower than traditional thermal reforming processes—are sufficient to achieve high turnover frequencies. These mild conditions enhance energy efficiency while extending catalyst lifespan by minimizing sintering and deactivation. The catalyst’s robustness is exhibited by its sustained performance over multiple reaction cycles, signaling promising prospects for real-world durability.

The research team leveraged advanced characterization techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) to reveal nanoscale structural features responsible for catalytic behavior. Notably, the presence of highly dispersed active sites and synergistic metal-support interactions underpin the enhanced catalytic activity and stability. These findings underscore the critical role of nanostructuring in next-generation catalyst design.

Beyond laboratory-scale experiments, scaling-up considerations were addressed through continuous-flow reactor testing, demonstrating that the catalyst system can be effectively integrated into existing chemical infrastructure. Continuous operation conditions align with industrial process requirements, highlighting the technology’s translational potential. This positions the approach as a strong candidate for deployment in hydrogen refueling stations, portable power devices, and decentralized energy generation units.

The environmental implications of this technology transcend hydrogen production alone. By circumventing noble metals, it alleviates reliance on finite resources and geopolitical supply chain risks associated with precious metal mining and refining. Moreover, the ability to use formic acid—a compound that can itself be sourced renewably from biomass or CO₂ reduction pathways—creates a potentially closed loop for carbon and energy circulation, aligning with circular economy principles.

Another exciting facet is that the evolved CO₂ from formic acid decomposition can be captured and recycled, closing the carbon loop and mitigating greenhouse gas emissions. The coupling of this catalyst system with carbon capture technologies might open avenues for integrated renewable energy systems that collectively advance low-carbon objectives. This synergy could be a cornerstone for future clean energy roadmaps.

Critically, the research also paves the way for broader application of noble-metal-free catalysts in other important chemical transformations. Demonstrating that non-precious metals can rival or exceed conventional catalysts may inspire a paradigm shift in catalysis research, catalyzing a wave of innovation geared toward sustainable materials and processes. This aligns with policy trends and industrial incentives to greenify chemical manufacturing.

In summary, the study by Qiu et al. marks a transformative contribution to sustainable catalysis and hydrogen economy development. The highly efficient, thermally driven, heterogeneous catalytic decomposition of formic acid achieved without noble metals sets a new benchmark for clean hydrogen generation. Through meticulous catalyst engineering, mechanistic insight, and practical demonstration, this work advances the feasibility of low-cost, scalable hydrogen production technologies capable of supporting decarbonized energy futures.

As the world races to meet ambitious climate targets, innovations like these exemplify the essential intersection of fundamental science and engineering solutions. They illustrate how impactful breakthroughs require holistic understanding—from atomic-scale processes to device-level operation—and how collaborative research can address complex energy challenges. This hydrogen generation strategy holds promise not only for mitigating climate change but also for energizing economies with sustainable fuels and fostering resilient industrial ecosystems.

Looking ahead, further exploration into catalyst optimization, integration with renewable energy inputs, and lifecycle assessments will be crucial. Combination with renewable electricity for formic acid sustainable synthesis, and deployment within multi-modal energy systems, can maximize overall efficiency and carbon reduction potential. The path from laboratory innovation to commercial and societal impact will require sustained interdisciplinary effort and supportive policy frameworks.

Overall, the study represents a pivotal milestone illustrating how chemistry can power the green transition. By unlocking valuable hydrogen production from abundant, easy-to-store materials without precious metals, it delivers a compelling vision for the future of energy: clean, affordable, and accessible to all. Such advances provide hope and a tangible toolkit for global efforts striving to protect the planet while fueling progress.

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Subject of Research: Heterogeneous thermal catalysis for noble-metal-free hydrogen production from formic acid.

Article Title: Highly efficient heterogeneous thermal catalysis for noble-metal-free hydrogen production from formic acid.

Article References:
Qiu, L., Yao, L., Wang, P. et al. Highly efficient heterogeneous thermal catalysis for noble-metal-free hydrogen production from formic acid. Nat Commun (2025). https://doi.org/10.1038/s41467-025-67895-y

Image Credits: AI Generated

The oxygen evolution reaction, a critical half-reaction in water electrolysis, involves the transfer of multiple electrons and protons, rendering it inherently slow and energy-intensive. Traditionally, to overcome this kinetic bottleneck, noble metal-based catalysts such as iridium and ruthenium oxides have been employed. While these materials exhibit exceptional catalytic activity, their scarcity and exorbitant costs make the large-scale deployment of AEMWEs economically unfeasible. Consequently, the scientific community has been vigorously investigating alternative catalyst materials that offer both affordability and high performance.

Recent advancements have highlighted the remarkable potential of nickel-iron (Ni-Fe) mixed oxides as promising replacements for noble metal catalysts. These transition metal oxides exhibit intrinsic electrocatalytic activities complemented by favorable abundances and relatively low costs compared to noble metals. Despite these advantages, synthesizing Ni-Fe oxides with the desired amorphous structure and optimal stoichiometric balance has posed significant difficulties, often requiring complex and expensive procedures. The ability to tailor these materials’ properties through facile and scalable manufacturing processes has remained an unmet need in the field.

Addressing this gap, researchers led by Professors Carlo Santoro and Roberto Nisticò have pioneered a novel and straightforward sol-gel synthesis pathway to fabricate nanostructured amorphous Ni-Fe mixed oxides with precisely tunable Ni to Fe ratios. This sol-gel technique stands out due to its simplicity, affordability, and potential for scaling, offering a practical route to engineer electrocatalysts that marry high activity with operational robustness. By meticulously modulating the composition and structural properties of the resultant catalysts, the team sought to unravel the intricate relationships between material characteristics and electrocatalytic performance.

Extensive morphological and physicochemical characterizations revealed that the synthesized Ni-Fe oxides possess an amorphous architecture, which crucially influences their electronic and surface properties. Amorphous structures, devoid of long-range crystalline order, often foster a higher density of active sites and enhanced charge transport pathways, conditions that are favorable for the OER. The team systematically explored a range of Ni/Fe ratios, discovering that these stoichiometric adjustments significantly modulate the concentration of active Ni³⁺ species, particularly NiOOH, known to play a vital role in promoting oxygen evolution kinetics.

Electrochemical assessments utilizing rotating ring disk electrode methods provided compelling evidence of the Ni:Fe = 0.75:0.25 oxide variant’s superior catalytic activity. This specific composition achieved remarkably low overpotentials, with a value as low as 291 millivolts, positioning it among the most efficient earth-abundant OER electrocatalysts reported to date. Furthermore, when incorporated into the anode of lab-scale AEMWE devices operating at elevated temperatures (80 °C), this catalyst maintained outstanding current densities and demonstrated exceptional stability over 100 hours of continuous operation, underscoring its practical viability.

The impressive durability of these amorphous Ni-Fe oxides can be attributed to their structural resilience and the synergistic interactions between nickel and iron species within the mixed oxide matrix. The dynamic coexistence of various oxidation states and the flexibility provided by the amorphous framework facilitate sustained catalytic turnover while resisting degradation mechanisms commonly observed in crystalline counterparts. This stability is vital for enabling long-term device operation, a critical parameter for commercial exploitation.

Besides their intrinsic catalytic properties, these materials exhibit advantageous electronic structures conducive to effective charge transfer during the OER process. The electronic interplay between Ni and Fe centers tailors the binding energies of oxygen intermediates on the catalyst surface, an essential factor dictating reaction kinetics. The ability to fine-tune these interactions via stoichiometric variation represents a breakthrough in catalyst design, enabling unprecedented control over activity and selectivity without resorting to precious metals.

Building on these promising results, the research team envisions further optimization of the catalyst morphology and surface chemistry through advanced synthetic strategies. Modifications aimed at increasing surface area, introducing porosity, or incorporating heteroatoms could further amplify catalytic performance by expanding the accessible active sites and enhancing mass transport phenomena. Moreover, coupling these electrocatalysts with engineered electrode architectures may unlock new avenues toward integrating AEMWEs into scalable hydrogen production systems.

These developments hold profound implications for the broader green energy landscape. By circumventing the reliance on scarce noble metals and delivering robust, cost-effective catalysts, this research paves the way for economically viable hydrogen generation technologies. In light of global ambitions to reduce carbon footprints and transition to renewable energy sources, such breakthroughs in electrocatalyst design are pivotal for enabling the hydrogen economy to flourish at scale.

The collaborative nature of this research, bridging expertise across institutions including the University of Milano-Bicocca, CNR-ITAE, CNR-ICCOM, and ENEA Casaccia Research Center, exemplifies the interdisciplinary approach required to tackle intricate scientific challenges. The integration of materials science, electrochemistry, and chemical engineering principles underpins the successful realization of high-performance, durable electrocatalysts tailored for water electrolysis applications.

Publication of this work in the peer-reviewed journal Industrial Chemistry & Materials accentuates its scientific rigor and relevance to both academic and industrial audiences. Notably, the article’s availability through the Royal Society of Chemistry without article processing charges democratizes access, fostering wider dissemination and accelerating innovation across the field.

As hydrogen technologies continue to evolve, the advancement of affordable, active, and stable OER electrocatalysts such as these amorphous Ni-Fe oxides marks a significant milestone. Their adoption within AEMWE systems promises to catalyze progress toward sustainable energy infrastructures, supporting global efforts to decarbonize industry and mitigate climate change. Continued research focusing on this class of catalysts will be instrumental in unlocking the full potential of green hydrogen.

Subject of Research:
Not applicable

Article Title:
Amorphous nanostructured Ni–Fe oxide as a notably active and low-cost oxygen evolution reaction electrocatalyst for anion exchange membrane water electrolysis

News Publication Date:
26-Mar-2025

Web References:
https://www.rsc.org/journals-books-databases/about-journals/industrial-chemistry-materials/

References:
DOI: 10.1039/D5IM00008D

Image Credits:
Carlo Santoro and Roberto Nisticò, University of Milano-Bicocca, Italy.

Keywords

Green hydrogen, Oxygen evolution reaction, Anion exchange membrane water electrolyzers, Nickel-iron mixed oxides, Electrocatalyst, Sol-gel synthesis, Amorphous nanostructures, Renewable energy, Sustainable catalysis, Electrochemical water splitting, Noble metal alternatives, Electrocatalytic durability