Mechanochemical synthesis of Au, Pd, Ru and Re nanoparticles with lignin as a bio-based reducing agent and stabilizing matrix.

A versatile, low-energy and solvent-free method to access nanoparticles (NPs) of four different transition metals, based on a bottom-up mechanochemical procedure involving milling of inorganic precursors, is presented. Lignin, a biomass waste, was used effectively as a reducing agent, for the first time in a mechanochemical context, to access MNPs where M = Au, Pd, Ru, Re. A series of metal precursors was used for this reaction and their nature was shown to be integral in determining whether NPs became incorporated within the organic lignin matrix, M@lignin, or not.

Hollow iron oxide nanoshells are active and selective catalysts for the partial oxidation of styrene with molecular oxygen.

Well defined hollow iron oxide nanoshells are active, selective and recyclable catalysts for the oxidation of styrene into benzaldehyde using difficult-to-activate molecular oxygen as the sole oxidant. Using no noble metals, unprecedented conversion of 90% was maintained while high selectivity of 73% was able to be achieved.