Polyamino amphiphile mediated support of platinum nanoparticles on polyHIPE as an over 1500-time recyclable catalyst

Abstract

For supported metal nanoparticles, the ligand/support is crucial to their catalytic activity, stability and recyclability. Here we show that a polyamino dendritic amphiphile is a versatile mediator for supported platinum nanoparticles (PtNPs). PEI@PS-EHA, a branched polyethylenimine (PEI) with a shell of poly(styrene-co-2-ethylhexyl acrylate) (PS-EHA), will self-assemble along the interface of a water-in-oil (W/O) emulsion, and stabilize a corresponding high internal phase emulsion (HIPE); after transformation of the HIPE into an open-cellular material termed polyHIPE, PEI@PS-EHA will act as a surface modifier to immobilize PtNPs. The supported catalyst is very fit for reduction reactions because the Pt species hardly leaches in a reductive environment (judged just from the leaching data, the catalyst can be recycled over 10 million times). No ripening of the supported PtNPs is found for over 1500 equivalent cycles, as judged from the apparent rate constant. The ready separation, high activity, extremely low metal leakage and high durability make the catalyst promising.