Stabilizing ultrafine intermetallics on carbon supports: from structural design to catalytic applications

Atomically ordered intermetallic nanoparticles possess well-defined crystal structures and atomic stacking patterns, which result in unique electronic structures and surface adsorption properties for catalytic applications. However, the high-temperature annealing required for atomic ordering inevitably accelerates metal sintering and promotes uncontrollable crystal growth, hindering the construction of ultra-dispersed nano-sized particles. Exploring preparation strategies for uniform and ultrafine (<5 nm) intermetallic nanoparticles therefore represents a critical research frontier in this field. The significance of achieving intermetallic nanoparticles with ultrafine scale remains undiminished for the foreseeable future. In this perspective, we focus on recent advancements in carbon-supported synthesis of ultrafine intermetallic compounds, including findings on targeted synthesis and catalytic applications of ultrafine-scale intermetallic nanoparticles. We review current synthetic strategies that not only yield ultrafine intermetallic phases but also allow precise control over catalyst structural properties for enhanced performances. Additionally, we highlight recent progress in applying ultrafine intermetallic phases to electrocatalytic applications. Finally, we address persistent bottlenecks and key challenges, offering insights into future directions for the synthesis and applications of ultrafine intermetallic compounds.