Intermetallic nanoparticles have long been celebrated for their unique physicochemical attributes, setting them apart from conventional alloy nanoparticles. Their crystalline ordering at the atomic scale imparts superior catalytic activity and selectivity, crucial for demanding applications such as fuel cells and sustainable ammonia synthesis. However, a significant challenge has persisted: ensuring that these nanoparticles maintain structural integrity and catalytic efficacy under harsh reaction conditions, where sintering and loss of active sites often degrade performance. Addressing this challenge, the research team developed an elegantly controlled two-step synthesis strategy that not only fabricates chemically ordered iNPs with a predetermined composition but also embeds them within a mesoporous carbon matrix, enhancing electron and mass transport while mitigating nanoparticle aggregation and dissolution.

Central to this transformation is a novel ligand-assisted interfacial assembly process that harnesses the self-organization of monomicelles at metal interfaces. By using a specially designed amphiphilic copolymer as a structure-directing agent, the researchers orchestrate the meticulous deposition of polymer micelles on substrates containing multiple metal precursors. Dopamine plays a dual role in this system, serving both as a carbon source and a coordinating ligand to stabilize metal ions during assembly. This synergy guides the formation of intricate metal–organic superstructures with well-defined architectures on nanoscale metal domains. The approach is highly versatile, accommodating an array of metal combinations that include noble metals such as platinum or palladium, alongside transition metals like iron and cobalt, known for their catalytic prowess.

Following this interfacial monomicelle assembly, the fabricated metal–organic structures undergo a precisely calibrated thermal treatment in an ammonia atmosphere. This step is pivotal as it induces the chemical ordering of the constituent metals into intermetallic phases while simultaneously carbonizing the dopamine-based precursor to form a robust mesoporous carbon network. The ammonia environment enhances nitrogen doping in the carbon matrix, further augmenting electrical conductivity and catalytic interfaces. The resultant material exhibits a harmonic integration of structurally ordered iNPs confined within a porous carbon host—an architecture that significantly elevates catalyst durability and electrochemical performance by facilitating rapid reactant diffusion and electron transfer.

The researchers have demonstrated the practical application of their method on systems comprising up to eight metallic elements, a complexity level rarely achieved with controlled phase purity and ordering. By fine-tuning parameters within the synthesis sequence, such as ligand concentration, metal ratios, and thermal treatment conditions, they can manipulate phase formation, degree of atomic ordering, and morphological features, enabling custom-tailored catalytic nanocomposites. This precise control allows for systematic studies into the synergistic effects of multiple metals on catalytic behavior, opening pathways for designing catalysts tailored to specific electrochemical reactions with enhanced efficiency and selectivity.

The robustness and functionality of the resulting mesoporous carbon-supported iNPs were verified through extensive characterization techniques. Electron microscopy unveiled uniform dispersions of nanoscale ordered domains encapsulated in porous carbon shells, while X-ray diffraction confirmed the formation of distinct intermetallic phases with long-range atomic ordering. Nitrogen sorption isotherm analyses revealed the mesoporous nature of the carbon matrix, vital for catalytic applications that depend on facile mass transport. These sophisticated characterizations underpin the reproducibility and reliability of the synthetic strategy, establishing it as a powerful platform for creating advanced catalytic materials.

Significantly, the protocol extends beyond materials synthesis to encompass detailed electrochemical applications targeting pressing energy and environmental challenges. Two key reactions were explored: the oxygen reduction reaction (ORR), fundamental for fuel cell technologies, and the nitrate reduction reaction (NO_3^-RR) aimed at sustainable ammonia production. Both reactions benefit immensely from catalysts that combine high activity, selectivity, and resilience under operational stress. The mesoporous carbon-embedded iNPs exhibited superior performance metrics in these reactions, attributed to their optimized electronic structures, enhanced active site accessibility, and improved catalyst longevity facilitated by mesoporous confinement.

Investigations into the catalytic mechanisms were advanced using in situ Fourier-transform infrared spectroscopy and online differential electrochemical mass spectrometry. These state-of-the-art tools allowed real-time monitoring of reaction intermediates and product evolution, providing mechanistic insights into how the iNPs mediate complex electrochemical processes. Such operando studies are critical for rational catalyst design, enabling the identification of active sites, reaction pathways, and deactivation modes, guiding future improvements in catalytic materials derived from this synthesis approach.

Overall, this research embodies a significant leap in nanomaterials engineering and catalysis science. The generalized and versatile ligand-assisted monomicelle assembly method not only achieves the integration of complex multimetallic iNPs into protective carbon matrices but also allows customization of structural and compositional features to suit diverse electrochemical applications. The comprehensive protocol spanning synthesis, characterization, and application equips the scientific community with a valuable toolkit to tackle the growing demands for efficient and durable catalytic systems in an era focused on clean energy and sustainable chemical production.

From a practical standpoint, the entire synthetic procedure requires approximately five days, balancing sophisticated chemical design with manageable timescales for laboratory implementation. Physical characterization employing electron microscopy, X-ray diffraction, and nitrogen sorption requires an additional two days. Electrochemical mechanism studies, encompassing in situ infrared spectroscopy and mass spectrometry, can be completed within 4–6 hours. This workflow offers scalability and accessibility, enabling researchers to adopt and adapt the protocol for specific research goals or industrial process developments.

The strategy’s incorporation of ammonia during the thermal treatment step is particularly ingenious, simultaneously promoting intermetallic phase formation and enhancing the mesoporous carbon structure with nitrogen heteroatoms. This nitrogen doping is a known technique to improve electrical conductivity and catalytic functionalities in carbon-based materials, further boosting the overall catalytic efficiency and stability of the composite. The multifunctionality of dopamine as both a carbon precursor and metal-coordinating ligand underscores the thoughtful integration of chemical components to streamline the synthesis process.

Moreover, the platform’s adaptability to a wide diversity of metal systems, including noble–transition metal combinations, heralds new avenues for exploring novel composition–structure–property relationships in catalysis. The ordered intermetallic phases formed provide unique electronic environments that can modulate reaction energetics, potentially unlocking enhanced reaction kinetics and product selectivities unimaginable with conventional catalysts. By embedding these phases within a mesoporous carbon host, this method overcomes the classic trade-off between catalytic activity and stability.

In the broader context of sustainable energy research, these advances resonate profoundly. Given the urgent global focus on clean energy vectors such as hydrogen fuel cells and greener pathways for ammonia synthesis—critical for fertilizer production—the ability to engineer catalysts capable of delivering on both performance and durability at scale is transformative. This protocol lays essential groundwork toward realizing economical and sustainable electrocatalytic systems that can operate efficiently over long durations with minimal degradation, a cornerstone for industrial adoption.

In conclusion, the ligand-assisted interfacial monomicelle assembly approach pioneered by Qiu, Zhu, Li, and colleagues offers a powerful blueprint for the fabrication of next-generation intermetallic nanoparticle catalysts embedded in mesoporous carbon nanostructures. This multifaceted strategy addresses longstanding challenges in nanoparticle stability, catalytic activity, and processability, heralding a new era in catalyst design for electrochemical energy conversion and beyond. As the global pursuit of sustainable technologies accelerates, such advances in materials science will be critical in bridging laboratory innovations to real-world impact.

Subject of Research: Intermetallic nanoparticles integrated into mesoporous carbon nanostructures for advanced electrocatalysis

Article Title: Ligand-assisted interfacial monomicelle assembly to incorporate intermetallic nanoparticles into mesoporous carbon nanostructures

Article References:
Qiu, P., Zhu, G., Li, M. et al. Ligand-assisted interfacial monomicelle assembly to incorporate intermetallic nanoparticles into mesoporous carbon nanostructures. Nat Protoc (2026). https://doi.org/10.1038/s41596-025-01326-6

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41596-025-01326-6

Central to this advancement is the revelation that catalyst activation is not merely a procedural step but the defining phase where the active catalytic species are actually formed. By employing cutting-edge operando techniques such as scanning electron microscopy and near-ambient pressure X-ray photoelectron spectroscopy, the scientific team decoded the transformations occurring at the catalyst surface during activation. These insights firmly establish that the evolution of a porous iron-based structure, coated by a mobile potassium species, lies at the heart of catalytic activity enhancement.

The role of promoters within these catalysts emerges as a pivotal theme. Frequently overshadowed in conventional understanding, promoters such as potassium, calcium, and aluminum oxides act cooperatively to engineer cementitious mineral phases. These phases are not mere spectators; they actively stabilize the overall catalyst architecture, bolstering the hierarchical porous network that sustains reactivity under industrially relevant conditions. Furthermore, the discovery of a highly dispersed K+ species—dubbed ammonia K—acting as the kinetic driver or “pacemaker” of the catalytic process adds a new dimension to promoter function that was previously unappreciated.

This refined perspective unravels the complexity behind the mineral phases containing oxides of key elements like aluminum, silicon, and calcium. Rather than inert additives, these mineral constituents underpin structural robustness and durability, thereby mitigating catalyst deactivation pathways that have long plagued industrial ammonia synthesis. The synergy between these mineral phases and the iron-potassium catalytic surface confers a resilience that extends catalyst operational life while maintaining sustained reactivity.

Historically, the Fritz Haber Institute holds a distinguished position in the lineage of catalytic innovation, dating back to Fritz Haber himself, whose groundbreaking synthesis of ammonia revolutionized agriculture and chemistry worldwide. This latest work stands as a testament to that legacy, weaving together decades of surface science and catalysis research — including the Nobel-recognized contributions of Gerhard Ertl in understanding surface chemical processes — to illuminate the dynamic and often elusive behaviors within real-world catalysts.

Operationally, the activation phase with its promoter-induced transformations is now understood as a finely choreographed process in which chemical and structural rearrangements occur simultaneously. The formation of porous iron structures, enhanced by mobile potassium species dynamically interacting with adsorbed nitrogen and hydrogen, optimizes the surface for nitrogen activation—a rate-limiting step in ammonia synthesis. These novel insights challenge the previous static models, emphasizing the catalyst’s dynamic nature under working conditions.

The methodological prowess displayed in this research stems from the integration of operando microscopy and spectroscopy techniques. These allow scientists to observe the catalyst’s structural and chemical states in real time, under industrially relevant pressures and temperatures. Such a sophisticated approach enables the disentanglement of complex multi-component interactions and sheds light on the precise mechanisms by which promoters enhance activity and stability, a feat unattainable with traditional ex situ analyses.

Implications of this research extend far beyond academic interest; by decoding the functional roles of promoters and mineral phases, the study offers a blueprint for designing next-generation catalysts. These catalysts are predicted to exhibit not only higher efficiency but also greater sustainability, all vital for meeting the increasing global demand for ammonia with reduced energy footprints and lower environmental impact.

Moreover, the identification of ammonia K as a transient yet essential species presents new opportunities for catalyst tuning at the molecular level. By controlling the dispersion and mobility of such promoter species, catalyst performance and longevity can potentially be tailored, creating customized catalytic systems adapted to various industrial scales and feedstock compositions.

The revelation that the catalyst’s hierarchical porous architecture is integral to its function introduces an additional dimension to catalyst design. Porosity not only facilitates efficient gas transport but also provides extensive active surface area, balanced by the structural stability conferred by mineral-based cementitious phases. This intricate balance ensures optimal exposure of active sites while resisting mechanical and chemical degradation during prolonged operation.

These findings also contribute to a paradigm shift in industrial catalysis, promoting the concept that active catalytic surfaces are inherently dynamic entities. The insights affirm the necessity of evaluating catalysts under operando conditions to capture the transient species and transformations pivotal to their function, thereby moving beyond oversimplified static models that fail to encapsulate real-world performance.

Looking ahead, this research paves the way for more rational catalyst design strategies that integrate atomic-level insights with materials engineering. With global pressures to reduce energy consumption and carbon emissions intensifying, innovations stemming from such fundamental understanding may well redefine the industrial ammonia synthesis landscape, enhancing food security and sustainability simultaneously.

The collaborative effort between leading research institutions and industrial partners exemplifies how multidisciplinary approaches can unravel longstanding chemical enigmas. By bringing together expertise in inorganic chemistry, interface science, and advanced characterization methods, the team has set a new standard for catalyst research that blends fundamental science with practical industrial relevance.

In sum, this landmark study illuminates the complex interplay of promoters, mineral phases, and structural dynamics in multi-promoted ammonia synthesis catalysts. It redefines the activation process as a transformational step, integral to catalyst efficiency and durability, thereby opening avenues for future breakthroughs in catalytic ammonia production and beyond.

Subject of Research: Multi-promoted catalysts in ammonia synthesis and their activation mechanisms

Article Title: Decoding technical multi-promoted ammonia synthesis catalysts

News Publication Date: 21-Aug-2025

Web References: http://dx.doi.org/10.1038/s41467-025-63061-6

Image Credits: © FHI

Keywords

Ammonia synthesis, catalyst activation, multi-promoted catalysts, potassium species, operando microscopy, near-ambient pressure XPS, catalytic stability, porous iron structure, cementitious mineral phases, industrial catalysis, ammonia K species, catalyst design

At the heart of the study lies the ambitious goal of crafting enzymes capable of catalyzing Kemp elimination reactions—a model reaction of great interest due to its relevance in studying enzyme mechanisms and design strategies. Unlike traditional directed evolution approaches, this work harnesses modular assembly and sophisticated design algorithms to generate entirely new enzymatic backbones, finely tuned active sites, and enhanced catalytic capabilities without reliance on natural enzyme templates.

The initial backbone generation involved an ingenious modular strategy leveraging multiple homologous protein structures. Through precise alignment of five distinct imidazole glycerol-phosphate synthase (IGPS) protein backbones, segments were dissected and recombined at structurally conserved junctions. Computational sequence design refined these chimeric constructs, guided by position-specific scoring matrices to ensure stability and compatibility across fragments, thus generating thousands of candidate backbones tailored for subsequent catalytic modification.

To complement this, the research expanded its scope by mining sequence databases extensively, identifying thousands of IGPS homologues. These sequences underwent clustering and rigorous structural prediction via the latest AlphaFold2 implementations. The high-confidence models then entered a cycle of stability design focused on preserving structural integrity while allowing active site flexibility—a crucial balance for efficient catalysis.

Engineering the catalytic site itself was meticulously executed through theozyme modeling. By incorporating precise geometric constraints derived from quantum chemical calculations, the team employed Rosetta’s Matcher algorithm to embed catalytic residues within the designed scaffolds, optimizing their positioning to mimic transition states effectively. This level of geometrical rigor ensured that the catalytic apparatus would be primed for the Kemp elimination’s mechanistic demands.

Once the initial active sites were integrated, the designed enzymes underwent an exhaustive round of sequence optimization focused on the microenvironment surrounding the ligand and catalytic residues. Utilizing Rosetta’s sequence design within spatial proximity to the active site and leveraging mutational scanning data, the design process strategically narrowed the sequence landscape. A ‘fuzzy’-logic objective function balanced energy considerations, van der Waals interactions, solvation effects, and geometric fidelity, filtering millions of designs to identify promising candidates.

Active-site and core stabilization efforts pushed the designs closer to practical viability. Enumerating low-energetic mutations in the active site and scanning the broader protein structure for positions amenable to beneficial substitutions permitted iterative rounds of refinement. Employing FuncLib calculations allowed for the judicious combination of stabilizing mutations while avoiding deleterious effects, ultimately enhancing the robustness of the enzyme across diverse conditions.

Validation extended into computational dynamical analyses, where the preorganization of the active site was tested through rigid-body minimization simulations absent of ligands. Designs failing to maintain catalytic residue alignment beyond acceptable root-mean-square deviations were discarded, ensuring that functionally viable geometries were preserved intrinsically. Additionally, the congruence between model predictions from different computational approaches was verified to further guarantee reliability.

The iterative optimization of active-site constellations was key to achieving high catalytic efficiency. Targeted mutagenesis simulated via FuncLib—eschewing homologous sequence constraints due to the de novo nature of designs—facilitated exploration of sequence diversity while maintaining stability. The best-performing designs were advanced for experimental validation, narrowing the gap between in silico predictions and laboratory realization.

Protein expression protocols were developed with precision to ensure that the computationally designed enzymes could be produced reliably and at scale. Harnessing bacterial expression systems and affinity purification techniques, the team prepared high-purity samples essential for detailed biochemical characterization and crystallographic analysis, confirming the fidelity of designs from sequence to structure.

Activity assays monitored enzymatic function using spectrophotometric methods detecting product formation, enabling kinetic parameter determination under varying substrate concentrations. The data fitting to Michaelis-Menten kinetics provided insights into catalytic turnover rates and substrate affinity, highlighting the practical effectiveness of the computationally designed enzymes compared to natural counterparts.

Thermal stability assessments using nano differential scanning fluorimetry revealed the robustness of the new enzymes, a critical factor for potential industrial or therapeutic applications. The temperature ramping experiments showcased the engineered proteins’ ability to maintain structural integrity under stress, consistent with the stability enhancements incorporated during design.

Crystallographic studies offered definitive structural validation, with multiple enzyme variants crystallized and their structures solved to resolutions near or below 2.1 Å. These analyses verified the accuracy of the computational models and provided atomic-level insights into active-site architecture, substrate positioning, and dynamic features instrumental for catalysis.

To complement static structural data, extensive molecular dynamics simulations spanning multiple microseconds illuminated the enzymes’ dynamic behaviors in bound and unbound states. Employing enhanced sampling techniques and state-of-the-art force fields, these simulations elucidated substrate binding modes, active-site flexibility, and solvent interactions, painting a comprehensive picture of the catalytic process in motion.

Electrostatic Valence Bond (EVB) simulations further probed the reaction mechanism at a quantum-mechanical/molecular-mechanical interface, distinguishing between reactive substrate conformers and capturing transient states of the Kemp elimination process. These simulations offered quantitative free-energy profiles that correlated closely with experimental activity, underpinning the rationale behind the designed enzymes’ functionality.

Collectively, this multidisciplinary approach—spanning computational modeling, structural biology, biophysical characterization, and dynamic simulations—presents a paradigm shift in enzyme design. The researchers’ ability to computationally generate highly efficient Kemp eliminases from scratch portends transformative impacts on enzyme engineering, enabling custom biocatalysts for diverse chemical transformations without exhaustive laboratory evolution.

By harnessing sophisticated algorithms, thorough validation pipelines, and rigorous biochemical assays, the study sets a new standard for the scope and precision of computer-aided enzyme design. This breakthrough holds promise not only for academic exploration but also for practical applications in sustainable manufacturing, drug development, and synthetic biology, where tailored catalysts can accelerate innovation and reduce environmental impact.

The confluence of modular backbone assembly, advanced design algorithms, and comprehensive dynamic simulations represents a masterclass in modern enzymology, painting a hopeful future where enzyme engineering is limited only by imagination and computational power. This work invites further refinement and expansion, including exploration of other challenging reactions and incorporation of allosteric regulation, ushering in an era of bespoke enzymes crafted entirely by computation.

Subject of Research: Computational design and engineering of high-efficiency Kemp elimination enzymes.

Article Title: Complete computational design of high-efficiency Kemp elimination enzymes.

Article References:
Listov, D., Vos, E., Hoffka, G. et al. Complete computational design of high-efficiency Kemp elimination enzymes. Nature (2025). https://doi.org/10.1038/s41586-025-09136-2

Image Credits: AI Generated