Under certain temperature (or temperature and pressure) conditions, mesoporous powders first collapse at the “weak bridges” (weakly connected portions of the framework) into highly surface active nanofragments, promoting particle aggregation and fusion. This facilitates a reduction in the sintering temperature of the material, thereby protecting functional moieties that are prone to deactivation at high temperatures and enabling the low temperature preparation of structural functional integrated ceramics. This is of great significance. Among the challenges, how to uniformly disperse functional moieties into the pores or walls of mesoporous powders is a prerequisite for designing and constructing high performance structural functional integrated ceramics.
To address these requirements, the team of Professor Wei Luo and Associate Professor Pengpeng Qiu from the State Key Laboratory of Advanced Fiber Materials and the College of Materials Science and Engineering at Donghua University recently developed a highly general and controllable “ligand assisted interfacial monomicelle assembly + NH₃ carbonization” strategy. This approach successfully achieves the in situ assembly of intermetallic nanoparticles (iNPs) in mesoporous carbon (mC) supports. The relevant results were published in Nature Protocols under the title “Ligand assisted interfacial monomicelle assembly to incorporate intermetallic nanoparticles into mesoporous carbon nanostructures”. This method uses metal dopamine block copolymer composite monomicelles as building units. Through a one step thermal treatment, the simultaneous ordering of metal atoms, mesopore formation in the carbon framework, and in situ anchoring of iNPs into the mesopore walls are realized. This effectively overcomes the common problems encountered in traditional methods, such as easy agglomeration of iNPs, inhomogeneous size distribution, and weak interactions with the support. The strategy enables precise control over the composition of iNPs (from binary to octonary), atomic ordering degree (0–95%), and crystalline phases (e.g., L1₀, L1₂), and can be adapted to carbon supports with various morphologies including zero , one , and two dimensional structures.
Figure 1 | Schematic illustration of different synthetic methods for loading iNPs onto carbon supports.
a, Co precipitation/post grafting process followed by high temperature reduction treatment. b, Wet impregnation process, where the mesoporous carbon support is first prepared, and then metal precursors are introduced into the mesopores via vacuum filtration or surface functionalization. c, Ligand assisted interfacial monomicelle assembly strategy followed by NH₃ annealing (exemplified by monomicelle assembly on a 2D carbon support). © 2026 Nature Protocols
Compared with traditional methods, the key distinctions of this strategy are: co precipitation and post grafting tend to block mesoporous channels; wet impregnation often leads to particle agglomeration due to capillary forces. In contrast, the present method achieves in situ anchoring of iNPs into the mesopore walls through the construction of metal organic superstructures and NH₃ carbonization, avoiding the above issues.
Figure 2 | Characterization of PtFeCoNiCu iNPs mC GO at different annealing temperatures.
a, XRD patterns. b, Calculated ordering degrees. c, Dark field STEM images and corresponding elemental mapping (scale bars, 50 nm). © 2026 Nature Protocols
Effect of annealing temperature on iNP ordering degree: XRD analysis shows that only amorphous metal clusters are present below 600 °C; a disordered face centered cubic PtFe phase appears at 650 °C; characteristic diffraction peaks of the L1₀ ordered phase (24.2° and 33.4°) start to emerge above 680 °C. As the temperature increases from 680 °C to 750 °C, the ordering degree rises from 30.5% to 82.1%. Using a two step NH₃ annealing (750 °C/120 min followed by 650 °C/120 min), the ordering degree reaches 93.8%. Dark field STEM and elemental mapping confirm that even at high temperatures, the various metal elements remain uniformly distributed.
Figure 3 | Characterization of Pt based iNPs mC GO from binary to octonary compositions.
a, XRD patterns. b, Dark field STEM images and corresponding elemental mapping (scale bars, 50 nm). c–i, Characterization of the quinary PtFeCoNiCu iNPs mC GO sample: c, Atomic resolution HAADF STEM image (scale bar, 1 nm); d, Corresponding FFT pattern along the [011] zone axis; e, Atomic resolution HAADF STEM image and corresponding elemental mapping (scale bar, 1 nm); f, Schematic illustration of elemental distribution over lattice sites superimposed on the HAADF image; g, Simulated atomic structure model; h, Column intensity profile along the red line in f; i, Atomic fraction of each element. © 2026 Nature Protocols
XRD analysis shows that from the binary PtFe to the octonary PtPdFeCoNiCuMn alloy system, characteristic diffraction peaks of the ordered L1₀ phase are present. Through atomic resolution HAADF STEM observation and elemental mapping, we demonstrate for the first time in a quinary alloy the ordered arrangement pattern where Pt atoms occupy the vertex positions while Fe/Co/Ni/Cu atoms occupy the face center positions. This finding provides the most direct structural evidence for the existence of intermetallic compounds.
Figure 4 | Detailed characterization of PdFe iNPs mC CF.
a, SEM image (scale bar, 200 nm). b,c, Atomic resolution HAADF STEM images and corresponding FFT pattern along the [100] zone axis (scale bars, 2 nm). d, Magnified atomic resolution HAADF STEM image, column intensity profile along the red line, and corresponding atomic scale EDS elemental mapping (scale bar, 1 nm). e, Comparative XRD patterns of ordered PdFe iNPs mC CF and disordered PdFe NPs mC CF. f, Quantitative evaluation of the peak areas of the (110) ordered peak relative to the (111) and (200) main peaks. g, N₂ adsorption desorption isotherms. h, Pore size distribution analysis. i, High resolution XPS spectra of the Pd 3d core level. j, High resolution XPS spectra of the Fe 2p core level. © 2026 Nature Protocols
Taking the binary PdFe system as an example, multi dimensional characterizations of the product are comprehensively presented: atomic resolution HAADF STEM confirms the alternating arrangement of Pd and Fe atoms in the L1₂ superlattice with an ordering degree of 95%; BET specific surface area is 400.10 m²/g, with a pore size of approximately 10 nm; XPS shows binding energy shifts of Pd and Fe, confirming electronic interactions within the alloy.
This work provides a novel approach for the design and controlled preparation of high quality functional ceramic powders, as well as for the low temperature construction of structural functional integrated ceramic materials. It is expected to promote the application of advanced ceramic materials under extreme environmental conditions.
Link to the paper: https://www.nature.com/articles/s41596-025-01326-6
