(85e) Flash Carbothermic Synthesis of Metallic Glass Nanoparticles with Expanded Compositional Space

Metallic glasses are promising materials for heterogeneous catalysis due to their unique amorphous structure and electronic properties. However, their application has been limited by strict formation conditions that constrain their compositional space, especially in nanoscale form where bottom-up synthesis remains challenging. In this work, we present a novel flash carbothermic reaction (FCR) method for the rapid synthesis of carbon-supported metallic glass nanoparticles (MGNPs) with significantly expanded compositional possibilities.

Our approach features ultrafast heating (>10⁵ K s⁻¹) and cooling rates (>10⁴ K s⁻¹) that kinetically suppress crystallization, enabling the formation of amorphous metal nanoparticles within milliseconds. By applying this method, we successfully synthesized various noble metal-based MGNPs with nine different compositional permutations (M₁-M₂-P, where M₁ = Pt/Pd, M₂ = Cu/Ni/Fe/Co/Sn). Through systematic experimental and computational studies, we demonstrate that the nanosize effect substantially enhances glass-forming ability, revealing that the composition space for nanoscale metallic glasses is significantly broader than for their bulk counterparts.

Comprehensive characterization through XRD, HRTEM, STEM-EDS, and XPS confirms the amorphous structure and homogeneous elemental distribution of the nanoparticles. The FCR method offers precise control over particle size (5-20 nm), composition, and substrate compatibility, while enabling high production rates (>70 g h^-1). Importantly, we successfully synthesized several MGNPs with compositions that have never been achieved in bulk form, including PdCoP, PdSnP, and high-entropy PdCuFeNiP.

As a proof-of-concept application, the PdNiP MGNPs demonstrate exceptional catalytic performance in Suzuki-Miyaura coupling reactions, achieving >99% yields under mild conditions and outperforming crystalline PdNi alloy catalysts. The enhanced activity is attributed to the synergistic metal-metalloid interactions and increased density of active sites in the amorphous structure. This work provides a versatile platform for designing high-performance heterogeneous catalysts beyond the constraints of crystal-phase materials, with potential applications extending to electrocatalysis, photocatalysis, and other advanced catalytic processes.