Wrapped up but still active: A platinum nanoparticle that is 2.2 nm in diameter and not coated by any stabilizing agent can be encapsulated in a hollow carbon shell 30–40 nm in diameter with a micro‐ to nanoporous wall structure (see picture). This encapsulated nanoparticle acts as an efficient and recyclable heterogeneous catalyst for various liquid‐phase hydrogenation reactions.

Spherical silica particles that are able to assemble at a phase boundary of a dual-phase mixture of water and an immiscible organic solvent were prepared by a partial modification of their surface hydroxyl groups with an alkylsilylation agent. Scanning electron microscopic observation of these particles in which their remaining surface hydroxyl groups had been selectively modified with colloidal gold particles revealed that each particle has an asymmetric surface structure: one side of the surface is hydrophilic and the other is hydrophobic. We found that these particles could form a micellar structure in water in the presence of an organic solution of a toluene/polystyrene mixture. The micellar structure was evidenced by formation of golf-ball-like polystyrene particles with dimples imprinting morphologies of the hydrophobic part of modified silica particles.

Auch eingewickelt noch aktiv! Ein Platin‐Nanopartikel von 2.2 nm Durchmesser, das von keinerlei Stabilisator umhüllt ist, kann mit einer hohlen Kohlenstoffschale umgeben werden, die einen Durchmesser von 30–40 nm und eine mikro‐ bis nanoporöse Wandstruktur aufweist (siehe Abbildung). Das so eingeschlossene Nanopartikel wirkt als effizienter und wiedergewinnbarer Heterogenkatalysator für verschiedene Hydrierungen in flüssiger Phase.