Morphology control of metallic nanoparticles supported on carbon substrates in catalytic conditions

Abstract Metallic nanoparticles are highly reactive objects, often used for their catalytic properties which strongly depend on their shape and morphology. Here we show that controlling the wetting properties on a substrate enables one to control the nanoparticle’s shape, prevent their coalescence and maximize their surface reactivity. The highly ordered mesoporous carbon structures (CMK) are ideal to achieve such a control. CMK can be tuned during their synthesis and display convex and concave surfaces capable of modifying the wetting properties and the morphology of the nanoparticles incorporated. On a concave substrate, the nanoparticle tends to spread on the surface of the substrate resulting in a platelet particle shape, while on flat or convex ones, the nanoparticle shows a limited wetting behavior corresponding to a spherical shape. In addition, the carbon enrichment of the metallic nanoparticles in contact with CMK plays a key role in controlling their equilibrium morphology. This atomic scale study allows us to better understand the interaction between metal nanoparticles and CMK in order to master their morphology and improve their reactivity.