image: Multiscale design framework for topology-engineered metamaterial catalysts. a, SEM images of sea urchin and starfish, (i) the microstructure of the ossicles of the starfish (ii) localized magnified microstructure (iii) the microstructure of the spine of the starfish (iv) localized magnified microstructure. b, Design concept of TPMS-based MG metamaterial scaffolds inspired by echinoderm stereom architectures. c, SEM images of G-type MG microlattices fabricated by AM process. d, SEM images of metamaterial catalysts fabricated via PED process. e, SEM images illustrating the hydrangea-like architecture of NiMo at the micro level. f, HAADF-STEM images of the NiMo atomic structure. g, Ni reaction sites in the atomic model of NiMo.
Credit: © National science review, Congrui Yang et al.
One catalyst, many jobs
Hydrogen produced from water using renewable electricity is widely viewed as a promising fuel for a low-carbon future. Yet an effective water-splitting electrode must perform several jobs at once. It must accelerate chemical reactions, continuously supply fresh electrolyte, clear away newly formed gas bubbles, withstand mechanical stress and remain stable over long periods. Because these tasks depend on structures ranging from atomic interfaces to millimeter-scale flow channels, improving one often comes at the expense of another.
Researchers led by scientists at Songshan Lake Materials Laboratory have now approached this challenge by designing the entire catalyst as a coordinated, multiscale system. Reported in National Science Review, their catalyst brings together two unusual forms of glass: a three-dimensionally printed metallic-glass (MG) scaffold and a nickel–molybdenum (NiMo) nanoglass coating. Each structural level is engineered to perform a different part of the catalytic process.
Printing highways for liquids and bubbles
The foundation of the catalyst is a zirconium-based metallic-glass framework fabricated by micro-laser powder bed fusion. Instead of printing a conventional porous foam or using a flat electrode, the researchers created triply periodic minimal surface structures—smooth, continuously curved networks containing interconnected channels.
Among the geometries examined, the Gyroid structure offered the best overall balance of permeability, liquid and gas transport, and mechanical robustness. Its open, winding channels act like a three-dimensional transport network, allowing electrolyte to reach the catalytic surface while giving the generated hydrogen and oxygen clear pathways to escape.
The team then coated the MG framework with NiMo amorphous particles using pulsed electrodeposition. The deposited layer formed a folded, flower-like surface that interacts with liquids and gases in two complementary ways: it is readily wetted by the electrolyte but has little affinity for gas bubbles. As a result, the electrolyte can spread rapidly across the catalyst, while newly generated bubbles detach before they grow large enough to cover active sites and obstruct transport.
Where two glasses meet
The design becomes even more distinctive at the atomic scale. Electron microscopy revealed that the coating is not a chemically uniform amorphous material. Instead, it contains compositionally distinct Ni-rich and Mo-rich glassy regions separated by abundant glass–glass interfaces.
These interfaces are neither conventional crystalline grain boundaries nor simple divisions between separate phases. They are highly disordered transition regions joining two amorphous domains with different compositions and local atomic environments.
Density-functional calculations showed that these glass–glass interfaces alter the local electronic structure of the catalyst. In particular, they create more favorable conditions for hydrogen adsorption and reduce the energetic requirement of a key step in the oxygen evolution reaction. The interfaces therefore serve as electronically active regions rather than passive structural boundaries.
When these features were brought together, the resulting Gyroid-based NiMo@G catalyst exhibited strong overall water-splitting performance. In 1 M potassium hydroxide, it achieved a current density of 100 mA cm⁻² at a cell voltage of 1.438 V. Separate durability measurements demonstrated stable operation for more than 200 hours.
Meanwhile, the printed MG scaffold maintained a compressive strength above 300 MPa, providing a robust backbone for the active nanoglass coating.
Designing from atoms to architecture
The central advance is not simply a new catalytic composition or a more permeable porous structure. It is the deliberate connection of functions across several length scales. At the atomic scale, glass–glass interfaces regulate adsorption and reaction energetics. At the microscale, the folded coating promotes electrolyte wetting and rapid bubble release. At the macroscale, the Gyroid architecture provides interconnected transport pathways and mechanical support.
In this way, the catalyst operates less like a collection of separate components and more like an integrated system: the interfaces accelerate reactions, the surface manages contact with liquids and gases, and the architecture keeps materials moving through the electrode.
The researchers suggest that this strategy could be extended to other metallic-glass scaffolds and multicomponent amorphous coatings. Further studies will be required to evaluate large-scale manufacturing, performance under industrial current densities and integration into practical electrolyzers.
Nevertheless, the work introduces a broader approach to catalytic metamaterials—one in which atomic interfaces, surface morphology and macroscopic transport networks are designed together. It not only offers a new design paradigm for catalytic metamaterials but also brings nanoglasses one step closer to practical applications in catalysis.