Precision synthesis of supported metal nanoparticles: a solid-state chemical approach and the mechanistic understanding

Supported nanoparticles are essential materials for various fields, including catalysis, biomedicine, and sensors. However, achieving precise control over their sizes and dispersion remains a significant challenge. In this work, we demonstrate that a solid-state approach, typically considered more challenging to control than solution-based methods, can be used for the precision synthesis of supported metal particles with a narrow size distribution and uniform dispersion. The key to success lies in utilizing the surface-confined nature of solid-state synthesis to enable localized nucleation, minimal particle migration, and a restricted supply of active metal species for the growth of each nucleus, as exemplified by the synthesis of Pt and Pd nanoparticles on porous carbon supports. Furthermore, by combining multiple in situ and ex situ characterization techniques with computational studies, we gain a systematic atomic-level understanding of the synthesis mechanisms. We believe that the presented synthesis approach and the atomic-level mechanistic understanding provide a solid foundation for achieving precision synthesis of supported nanoparticles with more complex structures and compositions, such as alloys and oxides, which are essential materials for numerous green energy technologies.